CN118073060B - Magneto-resistive rotary transformer for underwater environment, application and production process thereof - Google Patents

Abstract

The invention discloses a reluctance type rotary transformer for an underwater environment, application and a production process thereof, which belong to the field of absolute angle position detection of the underwater environment, and comprise a fixed seat gland, a spindle nose gland, a waterproof type single-pair pole rotor, a terminal gland and a rotor lengthening shaft which are coaxially and sequentially arranged, wherein a waterproof type eight-slot stator is also arranged between the waterproof type single-pair pole rotor and the inner wall of the terminal gland, and the waterproof type eight-slot stator and the waterproof type single-pair pole rotor are concentrically arranged; waterproof windings are wound on the waterproof eight-slot stator, and the waterproof windings penetrate out of the fixed seat gland through waterproof leads and are connected with the watertight plug. The magneto-resistive rotary transformer for the underwater environment, the application and the production process thereof can be used for the underwater environment through waterproof treatment, and the magneto-resistive rotary transformer with eight grooves and one pair of poles in a groove-pole fit mode has the advantages of being higher in precision, smaller in overall size and the like, so that the occupied space of the magneto-resistive rotary transformer integrated on the underwater robot is reduced.

Description

A reluctance rotary transformer for underwater environment, use and production process thereof

Technical Field

The present invention relates to the technical field of absolute angle position detection in underwater environment, and in particular to a reluctance rotary transformer for underwater environment, its application and its production process.

Background Art

A vector thruster is a device that can achieve omnidirectional propulsion. It can not only provide forward thrust for objects moving in space, but also provide thrust or torque in the pitch, roll, yaw and other directions of the object. There are currently three main ways to implement vector thrusters. The first is to control the direction of the thrust of the thruster through a mechanical structure. The second is to drive the propeller to generate lateral force by changing the pitch. The third is to use periodic speed regulation to change the instantaneous speed of the motor at the corresponding position of the propeller to generate lateral thrust.

When an underwater propulsion system uses a motor to achieve periodic speed regulation, it needs to be equipped with an asymmetric propeller, that is, different rotation speeds are applied at different angles within a rotation range of the propeller, so that corresponding torque can be generated to adjust the attitude of the underwater vehicle and realize functions such as turning, surfacing and diving. Through periodic speed regulation, the original underwater vehicle's functions such as surfacing, diving and turning can be realized with one motor. The underwater vehicle does not need to add a rudder or use multiple thrusters, replacing the traditional rudder plus propeller solution or multiple thruster solution, thereby simplifying the structure of the underwater vehicle, reducing costs and improving efficiency.

In order to accurately control the attitude of an underwater vehicle, it is necessary to detect and control the angle of the underwater vehicle. To this end, the new underwater vehicle developed by the US WHOI (Woods Hole Oceanographic Institution) detects the position of the motor by installing multiple Hall sensors on the motor and controls the motor speed to achieve periodic speed regulation. However, the accuracy of the Hall sensor in detecting the motor rotor position is low, and multiple Hall sensors need to be arranged.

At present, the methods used for detecting the position of the motor rotor include photoelectric encoders and rotary transformers. The above position sensors all have the following defects and shortcomings:

(1) Due to the lack of anti-corrosion structure, it will face problems such as high pressure, electrochemical corrosion, and biological adhesion in the underwater environment. It cannot be used directly in the underwater environment and must be installed in a sealed cabin, which makes the structure complicated and the cost increased.

(2) The propulsion system of underwater robots has high requirements for the reliability of position sensors. Ordinary sensors are prone to failure when subjected to vibration or impact.

The more reliable rotary transformers can be divided into brushed rotary transformers and brushless rotary transformers. Brushless transformers can be divided into wound rotary transformers and reluctance rotary transformers. The wound rotary transformers have waterproof windings on both the stator and the rotor, and a coupling transformer is installed on the coaxial position of the stator and the rotor; the reluctance rotary transformer uses a special rotor shape to make the rotor output a corresponding voltage at different angles. Both of the above-mentioned rotary transformers can only be used in the air and cannot be used directly in water.

In addition, the waterproof winding on the rotor of the brushed rotary transformer needs to be led out by brushes or slip rings, so the reliability is poor and the service life is short. The stator and rotor shafts of the brushless wound rotary transformer are equipped with a set of coupling transformers, which are larger in size and more complex in structure, and are also not suitable for harsh working conditions and seawater environments.

Summary of the invention

To solve the above problems, the present invention provides a reluctance rotary transformer for underwater environment, its use and its production process. It can be used in underwater environment through waterproof treatment. The reluctance rotary transformer with eight slots and single pole pairs has the advantages of higher precision and smaller overall size, thereby reducing the space occupied by the underwater robot. At the same time, it can also improve the accuracy of detecting the motor rotor position, improve the actual effect of motor periodic speed regulation, and improve the overall reliability of the motor rotor position sensor, thereby realizing precise control of the underwater vehicle.

In terms of single-pole rotary transformers, currently wound single-pole rotary transformers are mainly used, and the rotor adopts a skewed slot design, which is relatively complex in structure and not easy to waterproof. There are also single-pole equal-gap reluctance rotary transformers, etc. The present invention adopts an eight-slot single-pole slot-pole matched reluctance rotary transformer, which has higher precision than a four-slot single-pole. At the same time, the eight-slot design makes the overall size of the rotary transformer relatively smaller, thereby reducing the space occupied by the integration on the underwater robot. The underwater rotary transformer developed by the present invention can be used for motor rotor position detection of underwater motion devices such as underwater thrusters, underwater electric steering gears and underwater electric push rods.

To achieve the above-mentioned purpose, the present invention provides a reluctance rotary transformer for underwater environment, comprising a fixed seat gland, a shaft head gland, a waterproof single-pole rotor, an end gland, and a rotor extension shaft for connecting the motor shaft, which are axially and concentrically arranged in sequence, the waterproof single-pole rotor is placed in a cavity surrounded by the fixed seat gland and the end gland, and a waterproof eight-slot stator is further arranged between the waterproof single-pole rotor and the inner wall of the end gland, the waterproof eight-slot stator is concentrically arranged with the waterproof single-pole rotor, and a gap is left between the waterproof eight-slot stator and the waterproof single-pole rotor;

The waterproof eight-slot stator is wound with a waterproof winding, which is connected to a watertight plug after passing through a fixed seat gland via a waterproof lead.

Preferably, the waterproof single-pole rotor and the waterproof eight-slot stator are both formed by stacking multiple silicon steel sheets, the surface of each silicon steel sheet of the waterproof single-pole rotor is sprayed with ceramic, two adjacent silicon steel sheets of the waterproof eight-slot stator are welded at the weld, and ceramic is sprayed after welding, and the ceramic surface of the waterproof eight-slot stator is also covered with a nano-composite anti-corrosion coating.

Preferably, the waterproof winding is wound on the waterproof eight-slot stator in an eight-slot single-pole manner and fixed with epoxy AB glue, and the lead wire is a twisted pair lead-out and vulcanized waterproof winding;

The waterproof winding includes an excitation winding, a sine winding and a cosine winding which are sequentially wound on the stator teeth of the waterproof eight-slot stator. The number of turns of the excitation winding is between 15 and 20. The number of turns of the sine winding and the cosine winding are the same, and the number of turns of the sine winding and the cosine winding are both between 10 and 15.

Preferably, the waterproof single-pole rotor is a single-pole rotor with a sinusoidal air gap design:

Where r is the base circle radius; t is the angle; h is the maximum change height of the rotor; x(t) and y(t) represent the horizontal and vertical coordinates of the outer circle of the waterproof single-pole rotor, respectively.

Preferably, a positioning cylindrical boss is fixed at the center of one end of the rotor extension shaft toward the waterproof single-pole rotor, the silicon steel sheets of the waterproof single-pole rotor are arranged around the positioning cylindrical boss, and a positioning circular recess is provided on the shaft head pressure cover corresponding to the position of the positioning cylindrical boss, the positioning cylindrical boss is inserted into the interior of the positioning circular recess, and the positioning cylindrical boss is connected to the shaft head pressure cover via a countersunk screw.

Preferably, the ratio of the outer diameters of the waterproof eight-slot stator and the waterproof single-pole rotor is between 0.5-0.65, and the difference between the longest radius and the shortest radius of the waterproof single-pole rotor is between 1.5 mm and 2 mm.

Preferably, the watertight plug is electrically connected to the controller via the decoding unit, and the controller is electrically connected to the waterproof winding.

Preferably, the edge of the fixing seat gland is connected to the edge of the end gland via a countersunk screw;

A positioning boss for connecting to the motor end cover is fixed at the center of one side of the end cover away from the fixing seat cover, and the positioning boss is connected to the fixing seat cover via countersunk screws evenly arranged in an annular shape;

An annular positioning groove for assembling the waterproof eight-slot stator is provided on the inner wall of the end gland, and the outer wall of the waterproof eight-slot stator protrudes outward to form a positioning protrusion, which is inserted into the positioning groove provided on the annular positioning groove;

The rotor extension shaft, end gland, shaft head gland and fixed seat gland are all made of aluminum alloy plates with surface anodized hard treatment.

A purpose of a reluctance rotary transformer for underwater environment is used for detecting the position of a motor rotor in an underwater propeller, an underwater electric steering gear or an underwater electric push rod.

A production process of a reluctance rotary transformer for underwater environment comprises the following steps:

S1. Preparation of waterproof single-pole rotor:

Firstly, the shape of a waterproof single-pole rotor is designed based on a sinusoidal air gap, and then a silicon steel sheet is obtained by wire cutting according to the shape of the waterproof single-pole rotor. Then, ceramic is sprayed on the surface of the silicon steel sheet to obtain a silicon steel sheet for the waterproof single-pole rotor.

S2. Preparation of waterproof eight-slot stator:

Silicon steel sheets are obtained by wire cutting, and then the weld positions of the silicon steel sheets are welded to obtain a waterproof eight-slot stator. Then ceramics are sprayed on the waterproof eight-slot stator, and then a nano-composite anti-corrosion coating is applied. Then, an excitation winding is wound according to a winding method corresponding to an eight-slot single-pole pair, and then a sine winding and a cosine winding are wound in sequence. Then, the excitation winding, the sine winding and the cosine winding are adhered to the surface of the waterproof eight-slot stator by using epoxy AB glue, and the excitation winding, the sine winding and the cosine winding are led out by twisted pair wires to obtain waterproof leads. After the waterproof leads are vulcanized, they are passed through a fixing seat pressure cover and then connected to a watertight plug.

S3. Assembly:

The silicon steel sheets of the waterproof single-pole rotor are stacked around the positioning cylindrical boss on the rotor extension shaft, and the positioning circular concave boss of the shaft head gland is aligned with the positioning cylindrical boss of the rotor extension shaft and inserted, so as to press the waterproof single-pole rotor between the shaft head gland and the rotor extension shaft;

Then, use countersunk screws to fix the seat cover on the shaft head end cover, and set a waterproof eight-slot stator on the outside of the waterproof single-pole rotor, and then align the positioning groove with the positioning protrusion of the waterproof eight-slot stator to assemble the end cover, and finally use countersunk screws to assemble the end cover and the fixed seat cover.

The present invention has the following beneficial effects:

1. Waterproof each component: (1) The windings that have been waterproofed are wound around the stator teeth to protect them from seawater corrosion; (2) The silicon steel sheets that make up the stator and rotor are surface treated to prevent seawater corrosion; (3) The fixed seat gland, shaft head gland, and end gland are surface treated to prevent seawater corrosion; the sealless structure can be directly immersed in water for application in deep-sea high-pressure environments, and the dry cabin seal structure is simplified, reducing costs;

2. The eight-slot single-pole-pole matching reluctance rotary transformer has the advantages of higher precision and smaller overall size, thus reducing the space occupied by the underwater robot;

3. The use of a single-pole pair rotary transformer can obtain the absolute position of the motor shaft through the rotary transformer, which can realize both the position closed loop and the speed closed loop of the motor. In addition, the single-pole pair rotary transformer can be used to drive the motor to achieve periodic speed regulation, thereby achieving precise control of the underwater vehicle.

4. Pure mechanical structure, no electronic components, low failure rate, no need for sealing structure, simple structure.

The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is an exploded view of a reluctance rotary transformer for underwater environment of the present invention;

FIG2 is a cross-sectional view of a reluctance rotary transformer for underwater environment of the present invention;

FIG3 is a layout diagram of a waterproof eight-slot stator and a waterproof single-pole rotor of a reluctance rotary transformer for underwater environment of the present invention;

FIG. 4 is a schematic diagram of the waterproof winding of a reluctance rotary transformer for an underwater environment according to the present invention.

Among them: 1. Rotor extension shaft; 2. End gland; 3. Waterproof eight-slot stator; 31. Waterproof winding; 4. Waterproof single-pole rotor; 5. Shaft head gland; 6. Fixed seat gland; 7. Countersunk screw; 8. Motor shaft.

DETAILED DESCRIPTION

In order to make the purpose, technical scheme and advantages disclosed in the embodiments of the present invention clearer, the embodiments of the present invention are further described in detail in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not intended to limit the embodiments of the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions.

It should be noted that the terms "include", "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or devices.

Like reference numerals and letters denote similar items in the following drawings, and thus, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Multi-pole rotary transformers are mainly used to provide electrical angle position feedback for motors so as to control the motors and meet the motor speed regulation requirements. However, multi-pole rotary transformers cannot detect the absolute position angle of the motor rotor. Single-pole rotary transformers can detect the absolute position angle of the motor rotor in real time and meet the motor speed regulation requirements.

The present invention is designed based on the above analysis: as shown in Figures 1 to 4, a reluctance rotary transformer for underwater environment includes a fixed seat cover 6, a shaft head cover 5, a waterproof single-pole rotor 4, an end cover 2 and a rotor extension shaft 1 for connecting the motor shaft 8, which are axially concentrically arranged in sequence. Four countersunk holes for connecting the motor shaft 8 are reserved on the patented extension shaft in this embodiment. The waterproof single-pole rotor 4 is placed in a cavity surrounded by the fixed seat cover 6 and the end cover 2, and a waterproof eight-slot stator 3 is also arranged between the waterproof single-pole rotor 4 and the inner wall of the end cover 2. The waterproof eight-slot stator 3 is concentrically arranged with the waterproof single-pole rotor 4, and a gap is reserved between the waterproof eight-slot stator 3 and the waterproof single-pole rotor 4; a waterproof winding 31 is wound on the waterproof eight-slot stator 3, and the waterproof winding 31 is connected to a watertight plug after passing through the fixed seat cover 6 through a waterproof lead.

The waterproof single-pole rotor 4 and the waterproof eight-slot stator 3 are both formed by stacking multiple silicon steel sheets. The surface of each silicon steel sheet of the waterproof single-pole rotor 4 is sprayed with ceramic. The two adjacent silicon steel sheets of the waterproof eight-slot stator 3 are welded at the weld and sprayed with ceramic after welding. The ceramic surface of the waterproof eight-slot stator 3 is also covered with a nano-composite anti-corrosion coating, that is, ceramic can be used to resist seawater corrosion.

The nano-composite anti-corrosion coating described in this embodiment selects the special composite material for external anti-corrosion of WELLABLE Company: nano-composite emulsion metal primer 82314A, which is divided into a main agent and a curing agent, and the main agent/curing agent = 100/(1-3) (mass ratio). Before use, each component is stirred evenly, and then the ingredients are mixed according to the specified mixing ratio, stirred evenly again, and dried after brushing to face heavy anti-corrosion environment.

The waterproof winding 31 is wound on the waterproof eight-slot stator 3 in an eight-slot single-pole manner and fixed with epoxy AB glue to ensure that the winding will not loosen after winding is completed, and also to protect the winding. The lead wire is a twisted pair lead-out and vulcanized waterproof winding; the waterproof winding 31 includes an excitation winding, a sine winding and a cosine winding wound on the stator teeth of the waterproof eight-slot stator 3 in sequence, the number of turns of the excitation winding is between 15-20 turns, the number of turns of the sine winding and the cosine winding are the same, and the number of turns of the sine winding and the cosine winding are both between 10-15 turns.

The waterproof single-pole rotor 4 is a single-pole pair designed with a sinusoidal air gap.

Where r is the base circle radius; t is the angle; h is the maximum change height of the rotor; x(t) and y(t) represent the horizontal and vertical coordinates of the outer circle of the waterproof single-pole rotor, respectively.

A positioning cylindrical boss is fixed at the center of one end of the rotor extension shaft 1 facing the waterproof single-pole rotor 4. The silicon steel sheets of the waterproof single-pole rotor 4 are arranged around the positioning cylindrical boss. A positioning circular recess is provided on the shaft head cover 5 corresponding to the position of the positioning cylindrical boss. The positioning cylindrical boss is inserted into the positioning circular recess, and the positioning cylindrical boss is connected to the shaft head cover 5 via a countersunk screw 7 to ensure coaxiality.

Taking into account processing errors and environmental factors, and in order to increase the amplitude of the induced voltage of the sine winding and the cosine winding, the ratio of the outer diameters of the waterproof eight-slot stator 3 and the waterproof single-pole rotor 4 is between 0.5-0.65, and the longest radius and the shortest radius of the waterproof single-pole rotor 4 differ by 1.5mm-2mm.

The watertight plug is electrically connected to the controller via the decoding unit, and the controller is electrically connected to the waterproof winding.

The edge of the fixing seat gland 6 is connected to the edge of the end gland 2 via a countersunk screw 7;

A positioning boss for connecting the motor end cover is fixed at the center position of one side of the end cover 2 away from the fixed seat cover 6, and the positioning boss is connected to the fixed seat cover 6 through a countersunk screw 7 evenly arranged in a ring; an annular positioning groove for assembling the waterproof eight-slot stator 3 is provided on the inner wall of the end cover 2, and the outer wall of the waterproof eight-slot stator 3 protrudes outward to form a positioning boss, and the positioning boss is inserted into the positioning groove provided on the annular positioning groove to limit the circumferential rotation of the waterproof eight-slot stator 3; the rotor extension shaft 1, the end cover 2, the shaft head cover 5, and the fixed seat cover 6 are all made of aluminum alloy plates that have been hard-treated by anodizing on the surface. The aluminum alloy plates that have been hard-treated by anodizing on the surface can resist corrosion, high pressure and low temperature brought by the seawater environment, and are conducive to use in underwater environments.

A purpose of a reluctance rotary transformer for underwater environment is used for detecting the position of a motor rotor in an underwater propeller, an underwater electric steering gear or an underwater electric push rod.

In this embodiment, the countersunk screws 7 are all made of 316 stainless steel screws.

A production process of a reluctance rotary transformer for underwater environment comprises the following steps:

S1. Preparation of waterproof single-pole rotor 4:

Firstly, the shape of the waterproof single-pole rotor 4 is designed based on the sinusoidal air gap, and then a silicon steel sheet is obtained by wire cutting according to the shape of the waterproof single-pole rotor 4, and then ceramic is sprayed on the surface of the silicon steel sheet to obtain a silicon steel sheet for the waterproof single-pole rotor 4;

S2. Preparation of waterproof eight-slot stator 3:

A silicon steel sheet is obtained by wire cutting, and then the weld position of the silicon steel sheet is welded to obtain a waterproof eight-slot stator 3, and then ceramics are sprayed on the waterproof eight-slot stator 3, and then a nano-composite anti-corrosion coating is applied, and then an excitation winding is wound according to the winding method corresponding to the eight-slot single-pole pair, and then a sine winding and a cosine winding are wound in sequence, and then the excitation winding, the sine winding and the cosine winding are adhered to the surface of the waterproof eight-slot stator 3 by using epoxy AB glue, and the excitation winding, the sine winding and the cosine winding are led out by twisted pair wires to obtain waterproof leads, and then the waterproof leads are vulcanized, and then passed through the fixing seat pressure cover 6, and then connected to a watertight plug;

S3. Assembly:

The silicon steel sheets of the waterproof single-pole rotor 4 are stacked around the positioning cylindrical boss on the rotor extension shaft 1, and the positioning circular concave boss of the shaft head gland 5 is aligned with the positioning cylindrical boss of the rotor extension shaft 1 and inserted, so as to press the waterproof single-pole rotor 4 between the shaft head gland 5 and the rotor extension shaft 1;

Then, the seat cover 6 is fixed on the shaft head end cover by using the countersunk screw 7, and the waterproof eight-slot stator 3 is arranged on the outside of the waterproof single-pole rotor 4, and then the end cover 2 is assembled by aligning the positioning groove with the positioning protrusion of the waterproof eight-slot stator 3, and finally the end cover 2 and the fixed seat cover 6 are assembled by using the countersunk screw 7.

When in use, it is only necessary to connect the end gland 2 with the motor end cover, and connect the rotor extension shaft 1 with the motor shaft 8.

Therefore, the present invention adopts the above-mentioned reluctance rotary transformer for underwater environment, its use and its production process, which can be used in underwater environment through waterproof treatment, and utilizes the reluctance rotary transformer with eight slots and single poles, which has the advantages of higher precision and smaller overall size, thereby reducing the space occupied by integration on the underwater robot, and at the same time can also improve the accuracy of detecting the motor rotor position, improve the actual effect of motor periodic speed regulation, and improve the overall reliability of the motor rotor position sensor, thereby realizing precise control of the underwater vehicle.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims (7)

1. A production process of a reluctance rotary transformer for underwater environment, characterized in that: the reluctance rotary transformer for underwater environment comprises a fixed seat gland, a shaft head gland, a waterproof single-pole rotor, an end gland and a rotor extension shaft for connecting the motor shaft, which are axially and concentrically arranged in sequence, the waterproof single-pole rotor is placed in a cavity surrounded by the fixed seat gland and the end gland, and a waterproof eight-slot stator is further arranged between the waterproof single-pole rotor and the inner wall of the end gland, the waterproof eight-slot stator is concentrically arranged with the waterproof single-pole rotor, and a gap is left between the waterproof eight-slot stator and the waterproof single-pole rotor; The waterproof eight-slot stator is wound with a waterproof winding, which is connected to a watertight plug after passing through the fixed seat gland via a waterproof lead wire; The waterproof single-pole rotor and waterproof eight-slot stator are both made of multiple silicon steel sheets stacked together. The surface of each silicon steel sheet of the waterproof single-pole rotor is sprayed with ceramic. The adjacent two silicon steel sheets of the waterproof eight-slot stator are welded at the weld and sprayed with ceramic after welding. The ceramic surface of the waterproof eight-slot stator is also covered with a nano-composite anti-corrosion coating. The production process of a reluctance rotary transformer for underwater environment comprises the following steps: S1. Preparation of waterproof single-pole rotor: Firstly, the shape of a waterproof single-pole rotor is designed based on a sinusoidal air gap, and then a silicon steel sheet is obtained by wire cutting according to the shape of the waterproof single-pole rotor. Then, ceramic is sprayed on the surface of the silicon steel sheet to obtain a silicon steel sheet for the waterproof single-pole rotor. S2. Preparation of waterproof eight-slot stator: Silicon steel sheets are obtained by wire cutting, and then the weld positions of the silicon steel sheets are welded to obtain a waterproof eight-slot stator. Then ceramics are sprayed on the waterproof eight-slot stator, and then a nano-composite anti-corrosion coating is applied. Then, an excitation winding is wound according to a winding method corresponding to an eight-slot single-pole pair, and then a sine winding and a cosine winding are wound in sequence. Then, the excitation winding, the sine winding and the cosine winding are adhered to the surface of the waterproof eight-slot stator by using epoxy AB glue, and the excitation winding, the sine winding and the cosine winding are led out by twisted pair wires to obtain waterproof leads. Then, after the waterproof leads are vulcanized, they are passed through a fixing seat pressure cover and then connected to a watertight plug. S3. Assembly: The silicon steel sheets of the waterproof single-pole rotor are stacked around the positioning cylindrical boss on the rotor extension shaft, and the positioning circular concave boss of the shaft head gland is aligned with the positioning cylindrical boss of the rotor extension shaft and inserted, so as to press the waterproof single-pole rotor between the shaft head gland and the rotor extension shaft; Then, use countersunk screws to fix the seat cover on the shaft head end cover, and set a waterproof eight-slot stator on the outside of the waterproof single-pole rotor, and then align the positioning groove with the positioning protrusion of the waterproof eight-slot stator to assemble the end cover, and finally use countersunk screws to assemble the end cover and the fixed seat cover. 2. The production process of a reluctance rotary transformer for underwater environment according to claim 1 is characterized in that: the waterproof winding is wound on the waterproof eight-slot stator in the manner of eight-slot single-pole and fixed with epoxy AB glue, and the lead wire is a twisted pair lead-out and vulcanized waterproof winding; The waterproof winding includes an excitation winding, a sine winding and a cosine winding which are sequentially wound on the stator teeth of the waterproof eight-slot stator. The number of turns of the excitation winding is between 15 and 20. The number of turns of the sine winding and the cosine winding are the same, and the number of turns of the sine winding and the cosine winding are both between 10 and 15. 3. The production process of a reluctance rotary transformer for underwater environment according to claim 2 is characterized in that: the waterproof single-pole rotor is a single-pole pair shape designed with a sinusoidal air gap: ; In the formula, is the base circle radius; is the angle; is the maximum change height of the rotor; , They respectively represent the horizontal and vertical coordinates of the outer circle of the waterproof single-pole rotor. 4. The production process of a reluctance rotary transformer for underwater environment according to claim 3 is characterized in that: a positioning cylindrical boss is fixed at the center of one end of the rotor extension shaft facing the waterproof single-pole rotor, the silicon steel sheets of the waterproof single-pole rotor are arranged around the positioning cylindrical boss, and a positioning circular recess is provided on the shaft head pressure cover and corresponding to the position of the positioning cylindrical platform, the positioning cylindrical boss is inserted into the interior of the positioning circular recess, and the positioning cylindrical boss is connected to the shaft head pressure cover via a countersunk screw. 5. The production process of a reluctance rotary transformer for underwater environment according to claim 4 is characterized in that the ratio of the outer diameter of the waterproof eight-slot stator to the waterproof single-pole rotor is between 0.5-0.65, and the longest radius and the shortest radius of the waterproof single-pole rotor differ by 1.5mm-2mm. 6. The production process of a reluctance rotary transformer for underwater environment according to claim 5, characterized in that: the watertight plug is electrically connected to the controller via a decoding unit, and the controller is electrically connected to the waterproof winding. 7. The production process of a reluctance rotary transformer for underwater environment according to claim 6, characterized in that: the edge position of the fixing seat gland is connected to the edge of the end gland via a countersunk screw; A positioning boss for connecting to the motor end cover is fixed at the center of one side of the end cover away from the fixing seat cover, and the positioning boss is connected to the fixing seat cover via countersunk screws evenly arranged in an annular shape; An annular positioning groove for assembling the waterproof eight-slot stator is provided on the inner wall of the end gland, and the outer wall of the waterproof eight-slot stator protrudes outward to form a positioning protrusion, which is inserted into the positioning groove provided on the annular positioning groove; The rotor extension shaft, end gland, shaft head gland and fixed seat gland are all made of aluminum alloy plates with surface anodized hard treatment.