CN119030237A - Shaft-through marine permanent magnet shaft generator and assembly process - Google Patents

Abstract

The invention discloses a shaft-penetrating marine permanent magnet shaft-belt generator, comprising a coaxial generator stator shell, a generator stator flexure group, a generator permanent magnet rotor, a cylindrical rotor bracket and a central rotating shaft; the generator stator flexure group is fixed to the inner wall of the generator stator shell, and the generator permanent magnet rotor is coaxially fixed to the outer wall of the cylindrical rotor bracket; the inner wall of the cylindrical rotor bracket is integrally provided with a flange ring wall; a stator and rotor compartment is formed between the generator stator shell and the cylindrical rotor bracket; a flange plate is integrally provided coaxially in the middle of the central rotating shaft, and the a flange plate and the flange ring wall are synchronously connected coaxially by a plurality of flange bolts, so that the accurate and efficient assembly process of the large-scale marine shaft-penetrating generator can be smoothly implemented.

Description

Shaft-through marine permanent magnet shaft generator and assembly process

Technical Field

The invention belongs to the field of marine generators.

Background Art

With the development of the global economy, the development and utilization of marine resources have received increasing attention. As a means of marine transportation, the performance and reliability of the power unit of a ship are of great significance to shipping safety and economic benefits. As the core component of a ship's power unit, the performance of a marine shaft generator (hereinafter referred to as a shaft generator or motor) directly affects the power output and operating efficiency of the ship. Among the many forms of shaft generators, low-speed permanent magnet shaft generators have become the first choice for marine shaft generators in recent years because of their characteristics of no need for electrical excitation, high efficiency, no gearbox, high reliability, and wide adaptability.

Because the permanent magnet shaft-through type generator shares the main shaft with the ship's main shaft, the generator itself has no bearings and cannot operate independently, and its assembly process is complicated, which limits its development in the marine market. In view of this, our company has developed a permanent magnet shaft-through type generator structure and process flow that can be safely, quickly installed and disassembled, which is of great significance to improving the technical level of permanent magnet shaft generators in ship power devices and reducing operating costs;

At the same time, in practice, the indoor temperature in the generator compartment and diesel engine compartment of the ship is very high. At the same time, due to rain protection requirements, the device and the diesel engine are arranged in independent small-volume cabins in the same space. Due to its own heat dissipation and the heat dissipation of the diesel engine, the ambient temperature of the generator itself is relatively high, which in turn affects the heat dissipation efficiency of the generator when it runs at high speed.

Summary of the invention

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a shaft-penetrating marine permanent magnet shaft-belt generator and an assembly process, which can smoothly implement an accurate and efficient assembly process.

Technical solution: To achieve the above-mentioned purpose, the shaft-through-type marine permanent magnet shaft-belt generator of the present invention comprises a coaxial generator stator housing, a generator stator flexure group, a generator permanent magnet rotor, a cylindrical rotor bracket and a central rotating shaft;

The generator stator flexure group is fixed to the inner wall of the generator stator shell, and the generator permanent magnet rotor is coaxially fixed to the outer wall of the cylindrical rotor bracket; the inner wall of the cylindrical rotor bracket is integrally provided with a flange ring wall; a stator and rotor compartment is formed between the generator stator shell and the cylindrical rotor bracket; a flange plate is coaxially provided in the middle of the central rotating shaft, and the flange plate and the flange ring wall are coaxially and synchronously connected through a number of flange bolts.

Furthermore, flanges b and c are coaxially and integrally connected at both ends of the central rotating shaft; the outer diameters of flanges b and c are both smaller than the inner diameter of the flange ring wall.

Furthermore, it also includes a diesel engine output shaft and a propeller shaft, wherein the end of the diesel engine output shaft is coaxially integrated with a d flange, one end of the propeller shaft is coaxially integrated with an e flange, and the other end is connected to the propeller unit; the b flange and the d flange are coaxially and synchronously connected through a plurality of flange bolts; the c flange and the e flange are coaxially connected through flange bolts.

Furthermore, inner stoppers for installing end covers are provided at both ends of the inner wall of the generator stator housing, and two inner supporting circular end covers are coaxially provided at both ends of the generator stator housing, and the outer circles of the two inner supporting circular end covers are respectively inserted into the inner stoppers at both ends of the inner wall of the generator stator housing; the inner circle of the inner supporting circular end cover is coaxially fixedly connected to a copper ring through a flange, and a gap is formed between the inner circle of the copper ring and the outer wall surface of the cylindrical rotor bracket.

Furthermore, a plurality of ventilation holes are hollowed out on the inner supporting ring end cover, a cooling water inlet interface and a cooling water outlet interface are provided on the generator stator housing, a cooling water channel is provided in the generator stator housing, and both ends of the cooling water channel are respectively connected to the water inlet interface and the cooling water outlet interface.

Furthermore, it also includes an annular process end cover that can be installed at both ends of the generator stator housing, and the inner and outer rings of the annular process end cover are respectively provided with an inner ring flange hole and an outer ring flange hole; the outer ring flange hole of the outer ring of the annular process end cover is removably locked to the end of the generator stator housing by flange bolts; the inner ring flange hole of the inner ring of the annular process end cover is removably locked to the end of the cylindrical rotor bracket by flange bolts.

Further, the assembly process of the shaft-through type marine permanent magnet shaft generator:

Step 1: knock the outer ring of an inner supporting ring end cover coaxially into the inner stop of the inner wall of any end of the generator stator housing;

Step 2: Place the generator stator housing with the generator stator flexure group installed vertically on the workbench with the side where an inner support ring end cover has been knocked in as the bottom;

Step 3: hoist the integrated structure consisting of the cylindrical rotor bracket and the generator permanent magnet rotor from above the generator stator housing into the inner ring of the generator stator flexure group until the lower end of the cylindrical rotor bracket passes through the copper ring of the inner ring of the lower inner support ring end cover;

Step 4: Assemble the other inner support ring end cap with copper ring from above;

Step 5, turning over the assembly structure obtained in "Step 4" to a horizontal state;

Step 6: The outer ring flange holes of the two annular process end covers are detachably locked to the two ends of the generator stator housing through flange bolts; at the same time, the inner ring flange holes of the two annular process end covers are detachably locked to the two ends of the cylindrical rotor bracket through flange bolts; at this time, the two annular process end covers, the generator stator housing and the cylindrical rotor bracket together constitute a fixed body that is strictly constrained to each other. At the same time, under the rigid constraint of the flange connection of the two annular process end covers, the copper ring inner rings of the two inner supporting circular end covers and the cylindrical rotor bracket automatically enter a coaxial state, and a gap of 1±0.25mm is automatically formed between the two; at the same time, the stator and rotor bins are closed by the two annular process end covers, and the protection level reaches IP55;

Step 7: insert the central shaft into the inner ring of the cylindrical rotor bracket, and then tighten the flange plate and the flange ring wall through a number of flange bolts; then prepare to hoist it into the cabin;

Step 8. Lock flange b and flange d coaxially through several flange bolts; lock flange c and flange e coaxially through several flange bolts; at the same time, fine-tune the position of the generator stator housing adaptively; then remove the two annular process end covers, and measure the gap between the inner ring of the copper ring of the inner support circular end cover and the cylindrical rotor bracket at 4 places on the circumference. If there is a deviation, it can be fine-tuned through the jacking screw holes on the base foot; after the measurement is qualified, completely tighten the generator stator housing;

Step nine, when the extreme situation of stator short circuit occurs, remove the bolts connecting flange a and flange ring wall, and push the cylindrical rotor bracket axially out a certain distance. At this time, the rotor is disengaged from the central shaft.

Furthermore, an improved scheme for the cooling structure of the shaft-penetrating marine permanent magnet shaft-belt generator is provided, wherein a plurality of cold air outlets are distributed on the outer wall surface of the cylindrical rotor bracket, and the plurality of cold air outlets are distributed in a circular array at both ends of the permanent magnet rotor of the generator, and are all connected to the stator and rotor compartments;

The interior of the a flange is provided with a plurality of a gas centrifugal channels extending in the radial direction in a circumferential array, and the interior of the integrated structure formed by the cylindrical rotor support and the flange ring wall is provided with a plurality of b gas centrifugal channels in a circumferential array. The ends of the plurality of b gas centrifugal channels away from the axis of the cylindrical rotor support are connected to the stator and rotor bins through a plurality of cold air outlets. When the a flange and the flange ring wall are tightly connected through the flange, the ends of the plurality of a gas centrifugal channels away from the axis of the a flange are respectively connected to the ends of the plurality of b gas centrifugal channels close to the axis of the cylindrical rotor support; an annular gas diversion bin is coaxially arranged at the axis of the interior of the a flange, and the ends of the plurality of a gas centrifugal channels close to the axis of the a flange are all connected to the annular gas diversion bin. A gas diversion chamber is provided, wherein a section of air inlet channel a is provided in the length direction of the central rotating shaft, and the air inlet channel a is connected to the outside atmospheric pressure through an air inlet port at one end close to the b flange; a section of air inlet channel b is provided in the length direction of the propeller shaft, and when the c flange and the e flange are tightly connected through flanges, the ends of the air inlet channel a and the b flange are connected to each other; a section of air inlet channel c is provided in the length direction of the propeller shaft in parallel with the b section of air inlet channel, and a section of air inlet channel d is provided in the length direction of the central rotating shaft in parallel with the a section of air inlet channel; when the c flange and the e flange are tightly connected through flanges, the ends of the air inlet channel c and the d flange are connected to each other;

A tortuous gas cooling channel is arranged in the propeller hub or the propeller blade of the propeller unit, and the b-section air inlet channel and the c-section air inlet channel are connected to each other at one end close to the propeller unit through the tortuous gas cooling channel.

Beneficial effects: The present invention provides a quick-install and detachable permanent magnet through-shaft generator structure and process flow, which is of great significance for improving the technical level of permanent magnet shaft generators in ship power plants and reducing operating costs;

In particular, in "step six", the inner copper ring of the inner supporting ring end cover and the cylindrical rotor bracket are automatically coaxial and form a specific gap with the help of the process end cover, and in the subsequent "step eight", the process end cover is disassembled to restore the relative rotation relationship between the stator and the rotor under the coaxial condition; the process is ingenious, so that the device can be assembled smoothly and accurately;

At the same time, the improved air duct cooling circulation system enables the air continuously blown out from several cold air outlets to the stator and rotor bins is relatively cold air that has been efficiently cooled by the propeller blades. As a result, during the operation of the machine, cold air is continuously replenished in the stator and rotor bins of the device, thereby significantly promoting the cooling and heat dissipation of the motor stator flexure group and the stator and rotor bins.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the overall structure of the generator, in which the process end cover is not disassembled;

FIG2 is a schematic diagram of FIG1 after the process end cover is disassembled;

FIG3 is a cross-sectional view of a process end cover of a generator before and after disassembly;

FIG4 is a schematic diagram of all rotating components of this solution;

FIG5 is a cross-sectional view of the improved cooling air duct;

Figure 6 is a schematic diagram of the internal air duct of the propeller.

DETAILED DESCRIPTION

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figures 1 to 6, the shaft-through marine permanent magnet shaft-belt generator includes a coaxial generator stator housing 2, a generator stator flexure group 3, a generator permanent magnet rotor 11, a cylindrical rotor bracket 9 and a central rotating shaft 4; the generator stator flexure group 3 is coaxially fixed to the inner wall of the generator stator housing 2, and the generator permanent magnet rotor 11 is coaxially fixed to the outer wall of the cylindrical rotor bracket 9; the inner wall of the cylindrical rotor bracket 9 is integrally provided with a flange ring wall 7; a stator and rotor compartment 40 is formed between the generator stator housing 2 and the cylindrical rotor bracket 9.

An a-flange 6 is coaxially integrated in the middle of the central rotating shaft 4, and b-flange 8 and c-flange 5 are coaxially integrated at both ends of the central rotating shaft 4; in order to facilitate passing during assembly, the outer diameters of b-flange 8 and c-flange 5 are both smaller than the inner diameter of the flange ring wall 7.

As shown in Figures 4, 5, and 6, the diesel engine output shaft 30 and the propeller shaft 33 are also included. The output end of the diesel engine is driven and connected to the diesel engine output shaft 30. The end of the diesel engine output shaft 30 is coaxially integrated with a d flange 31. One end of the propeller shaft 33 is coaxially integrated with an e flange 32, and the other end is connected to the propeller unit 23; the b flange 8 is coaxially synchronously connected to the d flange 31 through a number of flange bolts; the c flange 5 is coaxially synchronously connected to the e flange 32 through a number of flange bolts; the a flange 6 is coaxially synchronously connected to the flange ring wall 7 through a number of flange bolts.

The inner ends of the inner wall of the generator stator housing 2 are provided with inner stoppers for mounting the end covers, and the two ends of the generator stator housing 2 are coaxially provided with two inner supporting circular end covers 1, and the outer circles of the two inner supporting circular end covers 1 are respectively inserted into the inner stoppers at the two ends of the inner wall of the generator stator housing 2, and are interference fit; the inner circle of the inner supporting circular end cover 1 is coaxially fixedly connected with a copper ring 51 through a flange, and a gap of 1±0.25mm is formed between the inner circle of the copper ring 51 and the outer wall surface of the cylindrical rotor bracket 9; a plurality of ventilation holes 12 are hollowed out on the inner supporting circular end cover 1, and a cooling water inlet interface 60 and a cooling water outlet interface 61 are provided on the generator stator housing 2, and a cooling water channel is provided in the generator stator housing 2, and the two ends of the cooling water channel are respectively connected to the water inlet interface 60 and the cooling water outlet interface 61, and under high load conditions, cooling water can be flowed from the water inlet interface 60 into the generator stator housing 2 through an external water pump to achieve the effect of forced heat dissipation.

As shown in Figures 1 and 2, it also includes two annular process end covers 10 that can be installed at both ends of the generator stator housing 2. The function of the two annular process end covers 10 is that in the assembly process, under normal use, the two annular process end covers 10 are in a removed state, and the inner and outer circles of the annular process end covers 10 are respectively provided with inner circle flange holes 10.1 and outer circle flange holes 10.2; the outer circle flange holes 10.2 of the outer circle of the annular process end cover 10 are detachably locked to the end of the generator stator housing 2 by flange bolts; the inner circle flange holes 10.1 of the inner circle of the annular process end cover 10 are detachably locked to the end of the cylindrical rotor bracket 9 by flange bolts.

Improvements to the cooling system of this solution (Figures 1 to 3 do not involve improvements to the cooling system):

As shown in FIGS. 5 and 6 , a plurality of cold air outlets 13 are distributed on the outer wall of the cylindrical rotor support 9 , and the plurality of cold air outlets 13 are distributed in a circular array at both ends of the generator permanent magnet rotor 11 , and are all connected to the stator and rotor bins 40 ;

A plurality of a gas centrifugal channels 24 extending in the radial direction are distributed in a circumferential array inside the a flange 6, and a plurality of b centrifugal channels 14 are distributed in a circumferential array inside the integrated structure formed by the cylindrical rotor support 9 and the flange ring wall 7. The ends of the plurality of b centrifugal channels 14 away from the axis of the cylindrical rotor support 9 are connected to the stator and rotor bins 40 through a plurality of cold air outlets 13 respectively. When the a flange 6 and the flange ring wall 7 are tightly connected through the flange, the ends of the plurality of a gas centrifugal channels 24 away from the axis of the a flange 6 are respectively connected to the ends of the plurality of b centrifugal channels 14 close to the axis of the cylindrical rotor support 9.

An annular gas diversion chamber 17 is coaxially arranged at the axis center of the a flange 6, and the ends of the a gas centrifugal channels 24 close to the axis center of the a flange 6 are all connected to the annular gas diversion chamber 17. A section a air inlet channel 15 is arranged in the central rotating shaft 4 along the length direction, and the a air inlet channel 15 is connected to the external atmospheric pressure through the air inlet 23 at the end close to the b flange 8; a section b air inlet channel 19 is arranged in the propeller shaft 33 along the length direction, and when the c flange 5 and the e flange 32 are tightly connected by flanges, the ends of the a section air inlet channel 15 and the b section air inlet channel 19 close to each other are connected to each other;

A c-section air inlet channel 20 is provided in the propeller shaft 33 along the length direction and is parallel to the b-section air inlet channel 19. A d-section air inlet channel 16 is provided in the central rotating shaft 4 along the length direction and is parallel to the a-section air inlet channel 15. When the c-flange 5 and the e-flange 32 are tightly connected by flanges, the c-section air inlet channel 20 and the d-section air inlet channel 16 are connected to each other at their ends close to each other.

A zigzag gas cooling passage 21 is provided in the propeller hub or propeller blade 22 of the propeller unit 23 , and the ends of the b-section air inlet passage 19 and the c-section air inlet passage 20 close to the propeller unit 23 are connected to each other through the zigzag gas cooling passage 21 .

How the cooling system works:

When working, the diesel engine drives the diesel engine output shaft 30 and then drives the central shaft 4 and the propeller shaft 33 to rotate synchronously, so that the propeller unit 23 is stirred in the water, thereby driving the hull forward. At the same time, the rotation of the central shaft 4 will drive the cylindrical rotor bracket 9 and the generator permanent magnet rotor 11 to rotate rapidly, so that the coil on the generator stator flexure group 3 cuts the magnetic flux lines to generate electricity, and continuously generates induced current, thereby achieving power generation while driving the hull forward. During the power generation process, the thermal effect of the current in the motor stator flexure group 3 generates heat, and the temperature in the stator and rotor compartment 40 will increase, thereby suppressing the power generation; at the same time, due to requirements such as rain protection, the device and the diesel engine are both arranged in an independent small-volume cabin in the same space. Due to its own heat dissipation and the heat dissipation of the diesel engine, the ambient temperature of the generator itself is relatively high, thereby limiting the heat dissipation capacity of the motor stator flexure group 3;

In the present case, during the high-speed rotation of the cylindrical rotor support 9 and the generator permanent magnet rotor 11, a swirling gas rotating around the axis is formed in the stator-rotor bin 40, so that the air at the several cold air outlets 13 on the outer peripheral wall of the cylindrical rotor support 9 presents a high flow velocity characteristic. According to fluid mechanics (Bernoulli equation), under the same conditions, the higher the flow velocity, the lower the air pressure, so that the stator-rotor bin 40 with a high flow velocity inside generates a certain suction force on the several cold air outlets 13; at the same time, the flange 6 and the cylindrical rotor support 9 are synchronously rotated along During the rotation of the axis, the air in the several a gas centrifugal channels 24 and b centrifugal channels 14 is centrifugally moved away from the axis of the cylindrical rotor support 9 under the action of centrifugal force; therefore, under the joint conduction of the centrifugal force on the air in the several a gas centrifugal channels 24 and b centrifugal channels 14 and the certain suction force generated by the stator and rotor bins 40 with high flow rate inside on the several cold air outlets 13, a continuous negative pressure is formed in the annular gas diversion bin 17, and then the negative pressure is finally transmitted to the air inlet 23, and the following gas cycle is formed:

The relatively high temperature air in the cabin is sucked into the a air inlet 15 through the air inlet 23 under the action of negative pressure, and then the air entering the a air inlet 15 flows through the b section air inlet 19, the zigzag gas cooling channel 21, the c section air inlet 20, the d section air inlet 16, the annular gas diversion chamber 17, a plurality of a gas centrifugal channels 24 and a plurality of b centrifugal channels 14 in sequence, and is finally blown out to the stator and rotor chamber 40 through a plurality of cold air outlets 13. At the same time, the excess air in the stator and rotor chamber 40 is re-discharged from the cabin through a plurality of ventilation holes 12 on the two inner support ring end covers 1, thereby forming the above-mentioned continuous gas flow cycle;

Since the propeller unit 23 is continuously stirred in the water, the heat of the propeller blades 22 on the propeller unit 23 will be quickly transferred to the water, thereby quickly dissipating the heat. During the above-mentioned gas flow circulation process, the hot air from the cabin will quickly take away the heat when flowing through the tortuous gas cooling channel 21 in the propeller blades 22, thereby cooling down. In the above-mentioned circulation process, the air continuously blown out from the plurality of cold air outlets 13 to the stator and rotor bins 40 is the cold air that has been efficiently cooled by the propeller blades 22. Therefore, during the operation of the machine, the stator and rotor bins 40 of the device are continuously replenished with cold air, thereby significantly promoting the cooling and heat dissipation of the motor stator flexure group 3 and the stator and rotor bins 40.

Assembly process:

Step 1: In the initial state, the generator stator housing 2 has a generator stator flexure group 3 fixedly installed on its inner wall, and then the outer ring of an inner support ring end cover 1 is coaxially knocked into the inner stop of the inner wall of any end of the generator stator housing 2 and locked;

Step 2: Place the generator stator housing 2 with the generator stator flexure group 3 installed vertically on the workbench with the side of the inner support ring end cover 1 knocked in as the bottom;

Step 3: hoist the integrated structure consisting of the cylindrical rotor support 9 and the generator permanent magnet rotor 11 from above the generator stator housing 2 into the inner ring of the generator stator flexure group 3 until the lower end of the cylindrical rotor support 9 passes through the copper ring 51 of the inner ring of the lower inner support ring end cover 1;

Step 4: Assemble the other inner supporting circular end cap 1 with the copper ring 51 from above by knocking it in and locking it;

Step 5, turning over the assembly structure obtained in "Step 4" to a horizontal state;

Step six, the outer ring flange holes 10.2 of the outer rings of the two annular process end covers 10 are detachably locked to the two ends of the generator stator housing 2 by flange bolts; at the same time, the inner ring flange holes 10.1 of the inner rings of the two annular process end covers 10 are detachably locked to the two ends of the cylindrical rotor bracket 9 by flange bolts; at this time, the two annular process end covers 10, the generator stator housing 2 and the cylindrical rotor bracket 9 together constitute a fixed body that is strictly constrained to each other. At the same time, under the rigid constraint of the flange connection of the two annular process end covers 10, the generator stator housing 2 and the cylindrical rotor bracket 9 automatically enter a coaxial state, and the inner rings of the copper rings 51 of the two inner supporting annular end covers 1 automatically enter a coaxial state with the cylindrical rotor bracket 9, and a gap of 1±0.25mm is automatically formed between the two; at the same time, the stator and rotor bins 40 are closed by the two annular process end covers 10, and the protection level reaches IP55, which plays a waterproof role in the subsequent hoisting and installation process;

Step 7: insert the central shaft 4 into the inner ring of the cylindrical rotor bracket 9, and then tighten the flange 6 and the flange ring wall 7 through a number of flange bolts; then prepare to hoist it into a relatively closed and rainproof cabin;

Step 8, coaxially lock the b flange 8 and the d flange 31 through a plurality of flange bolts; coaxially lock the c flange 5 and the e flange 32 through a plurality of flange bolts; at the same time, adaptively fine-tune the position of the generator stator housing 2;

Then disassemble the two annular process end covers 10, and measure the gap between the inner circle of the copper ring 51 of the inner supporting annular end cover 1 and the cylindrical rotor bracket 9 at 4 locations on the circumference to see if the gap value is 1±0.25mm. If there is a deviation, fine-tune it through the jacking screw holes on the base foot; after the measurement is qualified, completely tighten the generator stator housing 2;

Step nine, when an extreme situation of stator short circuit occurs, remove the bolts connecting the flange plate a 6 and the flange ring wall 7, and push the cylindrical rotor bracket 9 axially out by 20 mm. At this time, the rotor is disengaged from the central shaft 4.

The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims (8)

1. A shaft-penetrating marine permanent magnet shaft generator, characterized in that it comprises a coaxial generator stator housing (2), a generator stator flexure assembly (3), a generator permanent magnet rotor (11), a cylindrical rotor support (9) and a central rotating shaft (4); The generator stator flexure group (3) is fixed to the inner wall of the generator stator housing (2), and the generator permanent magnet rotor (11) is coaxially fixed to the outer wall of the cylindrical rotor bracket (9); the inner wall of the cylindrical rotor bracket (9) is integrally provided with a flange ring wall (7); a stator and rotor compartment (40) is formed between the generator stator housing (2) and the cylindrical rotor bracket (9); a flange plate (6) is integrally provided coaxially in the middle of the central rotating shaft (4), and the flange plate (6) and the flange ring wall (7) are coaxially and synchronously connected by a plurality of flange bolts. 2. The shaft-penetrating marine permanent magnet shaft generator according to claim 1 is characterized in that: the two ends of the central rotating shaft (4) are coaxially and integrally connected with a b flange (8) and a c flange (5); the outer diameters of the b flange (8) and the c flange (5) are both smaller than the inner diameter of the flange ring wall (7). 3. The shaft-penetrating marine permanent magnet shaft generator according to claim 2 is characterized in that it also includes a diesel engine output shaft (30) and a propeller shaft (33), the end of the diesel engine output shaft (30) is coaxially integrated with a d flange (31), one end of the propeller shaft (33) is coaxially integrated with an e flange (32), and the other end is connected to the propeller unit (23); the b flange (8) and the d flange (31) are coaxially synchronously connected through a plurality of flange bolts; the c flange (5) and the e flange (32) are coaxially connected through flange bolts. 4. The shaft-through marine permanent magnet shaft-belt generator according to claim 3 is characterized in that: inner stoppers for installing end covers are arranged at both ends of the inner wall of the generator stator housing (2), and two inner supporting circular end covers (1) are coaxially arranged at both ends of the generator stator housing (2), and the outer rings of the two inner supporting circular end covers (1) are respectively inserted into the inner stoppers at both ends of the inner wall of the generator stator housing (2); the inner ring of the inner supporting circular end cover (1) is coaxially fixedly connected with a copper ring (51) through a flange, and a gap is formed between the inner ring of the copper ring (51) and the outer wall surface of the cylindrical rotor bracket (9). 5. The shaft-through marine permanent magnet shaft-belt generator according to claim 4 is characterized in that: a plurality of ventilation holes (12) are hollowed out on the inner support ring end cover (1), a cooling water inlet interface (60) and a cooling water outlet interface (61) are provided on the generator stator housing (2), a cooling water channel is provided in the generator stator housing (2), and both ends of the cooling water channel are respectively connected to the water inlet interface (60) and the cooling water outlet interface (61). 6. The shaft-through marine permanent magnet shaft-belt generator according to claim 5 is characterized in that it also includes an annular process end cover (10) that can be installed on both ends of the generator stator housing (2), and the inner and outer rings of the annular process end cover (10) are respectively provided with an inner ring flange hole (10.1) and an outer ring flange hole (10.2); the outer ring flange hole (10.2) of the outer ring of the annular process end cover (10) is removably locked to the end of the generator stator housing (2) by flange bolts; the inner ring flange hole (10.1) of the inner ring of the annular process end cover (10) is removably locked to the end of the cylindrical rotor bracket (9) by flange bolts. 7. The assembly process of the shaft-through type marine permanent magnet shaft generator according to claim 6 is characterized in that: Step 1: knock the outer ring of an inner supporting circular end cover (1) coaxially into the inner stop of the inner wall of any end of the generator stator housing (2); Step 2: With the side of the inner supporting circular end cover (1) knocked in as the bottom, the generator stator housing (2) with the generator stator flexure group (3) installed is placed vertically on the workbench; Step 3, hoisting the integrated structure formed by the cylindrical rotor support (9) and the generator permanent magnet rotor (11) from above the generator stator housing (2) into the inner ring of the generator stator flexure group (3) until the lower end of the cylindrical rotor support (9) passes through the copper ring (51) of the inner ring of the lower inner support circular end cover (1); Step 4: Assemble the other inner supporting circular end cap (1) with the copper ring (51) from above; Step 5, turning over the assembly structure obtained in "Step 4" to a horizontal state; Step 6: The outer ring flange holes (10.2) of the outer rings of the two annular process end covers (10) are detachably locked to the two ends of the generator stator housing (2) through flange bolts; at the same time, the inner ring flange holes (10.1) of the inner rings of the two annular process end covers (10) are detachably locked to the two ends of the cylindrical rotor bracket (9) through flange bolts; at this time, the two annular process end covers (10), the generator stator housing (2) and the cylindrical rotor bracket (9) together constitute a fixed body that is strictly constrained to each other. At the same time, under the rigid constraint of the flange connection of the two annular process end covers (10), the inner rings of the copper rings (51) of the two inner supporting annular end covers (1) and the cylindrical rotor bracket (9) automatically enter a coaxial state, and a gap of 1±0.25mm is automatically formed between the two; at the same time, the stator and rotor bins (40) are closed by the two annular process end covers (10), and the protection level reaches IP55; Step 7: insert the central rotating shaft (4) into the inner ring of the cylindrical rotor support (9), and then tighten the flange plate (6) and the flange ring wall (7) by means of a plurality of flange bolts; and then prepare to hoist it into the cabin; Step 8, coaxially lock the b flange (8) and the d flange (31) through a number of flange bolts; coaxially lock the c flange (5) and the e flange (32) through a number of flange bolts; at the same time, finely adjust the position of the generator stator housing (2) adaptively; then disassemble the two annular process end covers (10), and measure the gap between the inner ring of the copper ring (51) of the inner supporting annular end cover (1) and the cylindrical rotor bracket (9) at 4 positions on the circumference, if there is a deviation, fine-tune it through the jacking screw holes on the base foot; after the measurement is qualified, completely tighten the generator stator housing (2); Step nine, when an extreme situation of stator short circuit occurs, remove the bolts connecting the flange plate (6) and the flange ring wall (7), and push the cylindrical rotor bracket (9) axially out a certain distance, at which time the rotor is disengaged from the central shaft (4). 8. The shaft-through marine permanent magnet shaft generator according to claim 5 is characterized in that: a plurality of cold air outlets (13) are distributed on the outer wall of the cylindrical rotor bracket (9), and the plurality of cold air outlets (13) are distributed in a circumferential array at both ends of the generator permanent magnet rotor (11), and are all connected to the stator and rotor bins (40); a plurality of a gas centrifugal channels (24) extending in the radial direction are distributed in a circumferential array inside the a flange (6), and the inside of the integrated structure formed by the cylindrical rotor bracket (9) and the flange ring wall (7) is circular. A plurality of b centrifugal channels (14) are arranged in an array around the rotor support (9), and the ends of the plurality of b centrifugal channels (14) away from the axis of the cylindrical rotor support (9) are connected to the stator and rotor chambers (40) through a plurality of cold air outlets (13). When the a flange (6) and the flange ring wall (7) are tightly connected through the flange, the ends of the plurality of a gas centrifugal channels (24) away from the axis of the a flange (6) are connected to the ends of the plurality of b centrifugal channels (14) close to the axis of the cylindrical rotor support (9); the a flange (6) is coaxially arranged at the axis center thereof. An annular gas diversion chamber (17) is arranged, and one end of a plurality of a gas centrifugal channels (24) close to the axis of the a flange (6) is connected to the annular gas diversion chamber (17); a section a air inlet channel (15) is arranged inside the central rotating shaft (4) along the length direction, and the a air inlet channel (15) is connected to the outside atmospheric pressure through an air inlet (23) at one end close to the b flange (8); a section b air inlet channel (19) is arranged inside the propeller shaft (33) along the length direction, and the c flange (5) is tightly connected to the e flange (32) through a flange. , the ends of the a-section air inlet channel (15) and the b-section air inlet channel (19) that are close to each other are connected to each other; a c-section air inlet channel (20) parallel to the b-section air inlet channel (19) is arranged in the propeller shaft (33) along the length direction, and a d-section air inlet channel (16) parallel to the a-section air inlet channel (15) is arranged in the central rotating shaft (4) along the length direction; when the c-flange (5) and the e-flange (32) are tightly connected by flanges, the ends of the c-section air inlet channel (20) and the d-section air inlet channel (16) that are close to each other are connected to each other; A zigzag gas cooling channel (21) is provided in a propeller hub or a propeller blade (22) of the propeller unit (23); the b-section air inlet channel (19) and the c-section air inlet channel (20) are connected to each other at one end close to the propeller unit (23) through the zigzag gas cooling channel (21).