CN113653701A

CN113653701A - Non-contact rudder angle feedback mechanism built in oil cylinder

Info

Publication number: CN113653701A
Application number: CN202111012780.8A
Authority: CN
Inventors: 秦伟然; 邱大宝; 朱晓光; 刘超; 方俊磊
Original assignee: 704th Research Institute of CSIC
Current assignee: 704th Research Institute of CSIC
Priority date: 2021-08-31
Filing date: 2021-08-31
Publication date: 2021-11-16

Abstract

The invention provides a non-contact rudder angle feedback mechanism arranged in an oil cylinder, which comprises: the magnetostrictive sensor is integrated on a sensor support at the tail part of the oil cylinder of the rudder pushing mechanism, a waveguide tube carried by the magnetostrictive sensor is arranged in the pressure-resistant outer tube, and the pressure-resistant outer tube is integrally arranged in a sleeve of the sensor support; the annular magnet is arranged at the tail end of the plunger and forms a detection loop with the waveguide tube. The invention has simple and compact structure and stable and reliable operation, can be applied to a conventional hydraulic steering engine and realizes the function of rudder angle feedback acquisition. Meanwhile, the rudder pushing mechanism is internally provided with a structure and has high protection performance, and the anti-soaking application of the rudder pushing mechanism can be realized.

Description

Non-contact rudder angle feedback mechanism built in oil cylinder

Technical Field

The invention relates to a non-contact rudder angle feedback mechanism arranged in an oil cylinder.

Background

The rudder angle feedback mechanism is arranged on the hydraulic steering engine steering mechanism, is used for realizing the real-time rudder angle acquisition function, is an important part for ship course control, and has high requirements on accuracy and reliability indexes.

The rudder angle feedback mechanism of the existing domestic hydraulic steering engine is generally realized by adopting the following two technical schemes:

a. a potentiometer/encoder gear type pull rod feedback mechanism is adopted;

b. a feedback mechanism in the form of a self-angle machine is adopted.

The prior art scheme a has more domestic ships and warships at present, and in the prior art scheme a, because the potentiometer/encoder has mechanical error and abrasion, and the gear type also has inherent phenomena such as gaps, the problems of poor precision and low service life easily occur after long-time use, and because the pull rod type is adopted, the problems of poor impact resistance are solved.

The installation space of the prior art scheme b is not suitable for some rudder pushing mechanisms, and the operation noise is high. And the maintenance cost is high due to the complex structure.

According to the prior art scheme a and b, when the tiller shakes up and down, the stable output of the rudder angle cannot be guaranteed.

Disclosure of Invention

The invention aims to provide a non-contact rudder angle feedback mechanism arranged in an oil cylinder.

In order to solve the above problems, the present invention provides a non-contact rudder angle feedback mechanism built in an oil cylinder, comprising:

the annular magnet is arranged on a plunger inside a refueling cavity of the oil cylinder, and the plunger outside the refueling cavity of the oil cylinder is connected with the tiller;

a magnetostrictive displacement sensor comprising: the electronic component is fixed on an oil cylinder outside the oil filling cavity, the electronic component is arranged at the end, far away from the plunger, of the oil cylinder, the waveguide extends into the oil filling cavity, a gap is formed between the waveguide and the annular magnet, a first magnetic field generated by the waveguide intersects with a second magnetic field generated by the annular magnet to generate current pulses, and the electronic component is coated with a protective shell; the electronic component is used for recording the time period required by the detected current pulse, multiplying the time period by a preset speed to obtain the displacement of the annular magnet and sending the displacement of the annular magnet to the controller;

and the controller is connected with the electronic component and used for receiving an input target rudder angle value of the rudder stock, calculating a current rudder angle value of the rudder stock based on the displacement of the annular magnet, and outputting corresponding hydraulic oil to the oil filling cavity based on a difference value if the target rudder angle value and the current rudder angle value have the difference value so as to drive the plunger to displace by a corresponding distance.

Further, in the non-contact rudder angle feedback mechanism with the built-in oil cylinder, the magnetostrictive displacement sensor further comprises a pressure-resistant outer pipe, and the waveguide pipe is arranged in a containing cavity of the pressure-resistant outer pipe.

Further, in the above-mentioned non-contact rudder angle feedback mechanism built in the cylinder, still include:

the end cover is closed at the end, far away from the plunger, of the oil cylinder, and an end cover through hole is formed in the end cover;

a sensor holder, the sensor holder comprising: the pressure-resistant outer tube is arranged in the sleeve, and is arranged in the pressure-resistant outer tube accommodating cavity.

Further, in the non-contact rudder angle feedback mechanism with the built-in oil cylinder, a sealing groove is circumferentially formed in the side wall of the through hole fixing portion of the sensor support, which is in contact with the end cover through hole, and a first sealing ring is arranged in the sealing groove.

Further, in the non-contact rudder angle feedback mechanism with an internal cylinder, a second seal ring is circumferentially arranged in a gap between the fixing through hole of the fixing portion and the pressure-resistant outer tube.

Further, in the non-contact rudder angle feedback mechanism built in the oil cylinder, a plunger through hole is formed in the tail end of a plunger in the oil filling cavity, an annular magnet and a magnetism isolating gasket are arranged on the inner side wall of the plunger through hole, the annular magnet and the magnetism isolating gasket are overlapped, through holes are formed in the annular magnet and the magnetism isolating gasket respectively, the through hole of the annular magnet, the through hole of the magnetism isolating gasket and the plunger through hole are aligned with each other, wherein the annular magnet is arranged close to the side of the near end cover, and the magnetism isolating gasket is arranged far away from the side of the near end cover;

the sleeve penetrates through the through hole of the annular magnet, the through hole of the magnetism isolating gasket and the through hole of the plunger and extends into the cavity of the plunger, and a circumferential gap is reserved between the sleeve and the annular magnet.

Further, in the non-contact rudder angle feedback mechanism arranged in the oil cylinder, the end cover is axially fixed with the oil cylinder far away from the plunger end through a bolt, the end cover is radially fixed with the oil cylinder far away from the plunger end through a clamping ring, and a fixing sleeve ring is sleeved outside the clamping ring.

Further, in the non-contact rudder angle feedback mechanism arranged in the oil cylinder, a joint surface between the end cover and the oil cylinder far away from the plunger end is sealed by a third sealing ring.

Further, in the non-contact rudder angle feedback mechanism arranged in the oil cylinder, an annular guide lining is arranged on the inner side wall of the oil cylinder, the outer side wall of the annular guide lining is in contact with the inner side wall of the oil cylinder, the inner side wall of the annular guide lining is in contact with the outer side wall of the plunger, and the guide lining is made of high-molecular wear-resistant materials.

Further, in the non-contact rudder angle feedback mechanism with a built-in oil cylinder, a V-shaped combined sealing ring is arranged in a gap defined by the guide bush, the outer side wall of the plunger and the inner side wall of the oil cylinder, wherein the V-shaped combined sealing ring is formed by overlapping a plurality of V-shaped sealing rings, and the cross section of each V-shaped sealing ring is V-shaped.

Compared with the prior art, the invention can realize the function of feedback acquisition of the steering engine rudder angle through the magnetostrictive sensor;

in addition, the invention eliminates abrasion and noise by adopting a non-contact rudder angle feedback mechanism through the magnetostrictive sensor, can avoid mechanical errors of a connecting rod type and a self-angle trimming machine, and can also greatly reduce the influence on the feedback precision caused by the shaking of a rudder stock in the movement process so as to improve the control precision of the rudder angle.

In addition, the displacement signal transmitted back by the magnetostrictive sensor is an absolute value signal. The condition of signal drift or value change does not exist, and the periodic re-calibration and maintenance are not needed as other displacement sensors, so that the problem of repeated adjustment of a feedback mechanism is thoroughly solved.

In addition, the rudder angle feedback mechanism is arranged in the oil cylinder, the influence of the feedback mechanism on the overall dimension of the rudder pushing mechanism can be reduced to the maximum extent, and the compact design of the rudder pushing mechanism is facilitated. The built-in structure ensures the EMC (electromagnetic compatibility) characteristic of the feedback mechanism.

Drawings

FIG. 1 is a schematic diagram of an external structure of a non-contact rudder angle feedback mechanism built in an oil cylinder according to an embodiment of the present invention;

FIG. 2 is an enlarged, fragmentary, schematic view of the first region of FIG. 1;

FIG. 3 is an enlarged, fragmentary, schematic view of the second region of FIG. 1;

FIG. 4 is a schematic illustration of a magnetostrictive sensor according to an embodiment of the invention in a disassembled state;

FIG. 5 is a schematic structural diagram of a sensor holder according to an embodiment of the invention;

FIG. 6 is a schematic view of a first magnetic field generated by a waveguide of one embodiment of the present invention intersecting a second magnetic field generated by the ring magnet;

FIG. 7 is a schematic view of the connection of the plunger and tiller according to an embodiment of the invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

As shown in fig. 1 to 7, the present invention provides a non-contact rudder angle feedback mechanism built in an oil cylinder, including:

the annular magnet 4 is arranged on the plunger 6 in the oil filling cavity 8 of the oil cylinder 5, and the plunger 6 outside the oil filling cavity 8 of the oil cylinder 5 is connected with the tiller 13;

magnetostrictive displacement sensor 1, comprising: the electronic component 9 is fixed on the oil cylinder 5 outside the oil filling cavity, the electronic component 9 is arranged at the end, far away from the plunger 6, of the oil cylinder 5, the waveguide 10 extends into the oil filling cavity, a gap is arranged between the waveguide 10 and the annular magnet 4, a first magnetic field 11 generated by the waveguide 10 and a second magnetic field 12 generated by the annular magnet 4 intersect to generate a current pulse 38, and a protective shell is coated outside the electronic component 9;

here, the protective case may be a stainless steel material;

a controller connected to the electronic component 9.

The waveguide 10 generates a first magnetic field 11, the electronic component 9 at the tail of the pressure-resistant outer pipe receives the intersection of the first magnetic field 11 generated by the waveguide 10 and the second magnetic field 12 generated by the ring magnet 4 to generate a current pulse 38, and the current pulse signal is output to an external controller through an aviation plug and a cable connected with the electronic component 9.

According to the invention, a gap is arranged between the waveguide tube 10 and the annular magnet 4, so that the magnetostrictive displacement sensor 1 is not in contact with the plunger 6, and the annular magnet 4 is driven by the plunger 6 to avoid mechanical friction between the annular magnet 4 and the waveguide tube 10 in the axial movement process of the oil filling cavity 8 of the oil cylinder 5.

The rudder angle feedback mechanism provided by the invention has the advantages of simple and compact structure and stable and reliable operation, and can be applied to a conventional hydraulic steering engine to realize the function of rudder angle feedback acquisition. Meanwhile, due to the built-in structure and the high protection (IP68) characteristic, the rudder pushing mechanism can be applied in a water immersion prevention mode.

In an embodiment of the non-contact rudder angle feedback mechanism with a built-in oil cylinder, the electronic component 9 is configured to record a time period required by a measured current pulse, multiply the time period by a preset speed to obtain a displacement of the ring magnet 4, and send the displacement of the ring magnet 4 to the controller;

the controller is used for receiving an input target rudder angle value of the rudder stock 13, calculating a current rudder angle value of the rudder stock 13 based on the displacement of the annular magnet 4, and outputting corresponding hydraulic oil to the oil filling cavity 8 based on a difference value if the target rudder angle value and the current rudder angle value have the difference value so as to drive the plunger 6 to displace by a corresponding distance.

Here, when the ring magnet 4 and the plunger 6 are relatively displaced, the first magnetic field 11 and the second magnetic field 12 intersect, and the generated current pulse is transmitted to the sensing coil of the electronic component 9 at a fixed speed of sound. The time period required from the moment when the current pulse is generated to the moment when the current pulse is detected by the sensor coil can be recorded, and the displacement of the ring magnet 4 can be accurately calculated by multiplying the required time period by the fixed speed.

The signal picked up by the electronic unit 9 directly reflects the displacement of the plunger, which signals the absolute position of the plunger movement to the controller.

The displacement of the plunger can be converted into a rotation angle of the tiller, namely a rudder angle value after the acquisition and operation of the controller.

The detection signal type of the controller can cover SSI signals, Profinet, canbus, analog quantity (4-20 mA) and other interface forms, the output signal of the sensor is an absolute value, a problem of data receiving cannot be caused even if the power supply is interrupted and reconnected, and zero adjustment is not needed. The sensing assembly is of a non-contact structure, and repeated sensing does not cause any abrasion to the sensor, so that the sensor has the characteristics of high precision, good reliability, no signal drift or value change and the like. The invention can realize the function of collecting rudder angle signals and can be applied to the conventional hydraulic steering engine with the oil cylinder pressure not more than 35 MPa.

Specifically, the projection distance from the center of the tiller to the axis of the plunger is constant and is C, the relative displacement between the plunger and the oil cylinder is L, and the rudder angle is theta, namely

Namely, rudder angle feedback acquisition is realized.

In an embodiment of the present invention, the controller may adopt an SSI signal interface, and data characteristics of the absolute position signal are as follows:

a length of 25 bits, a gray code,

the accuracy of the measuring head is 1um,

linearity < + 0.01% full scale (minimum +40 um);

repetition precision < + 0.001% full scale (minimum +2.5 um);

in another embodiment of the present invention, the feedback mechanism is characterized as follows:

feedback accuracy: not more than 0.2 degree;

steering speed: optionally;

oil cylinder pressure: 16 MPa;

the working temperature is-40 ℃ … +75 ℃.

Fig. 2 is an enlarged schematic view of a first region 15 in fig. 1, and as shown in fig. 1 and 2, in an embodiment of the non-contact rudder angle feedback mechanism with a built-in oil cylinder according to the present invention, the magnetostrictive displacement sensor 1 further includes a pressure-resistant outer tube 14, and the waveguide 10 is disposed in a cavity of the pressure-resistant outer tube 14 to protect the waveguide 10 against pressure and oil.

As shown in fig. 1 and 5, in an embodiment of the non-contact rudder angle feedback mechanism with a built-in oil cylinder, the non-contact rudder angle feedback mechanism further includes:

the end cover 3 is closed at the end, far away from the plunger 6, of the oil cylinder 5, and an end cover through hole is formed in the end cover 3;

a sensor holder 2, the sensor holder 2 comprising: the fixing part 17 and with the sleeve 18 that the fixing part 17 is connected, wherein, the fixing part 17 is fixed in the end cover through-hole, be provided with fixed through-hole on the fixing part 17, the one end of withstand voltage outer tube 14 is fixed in the fixed through-hole of fixing part 17, be provided with withstand voltage outer tube appearance chamber 21 in the sleeve 18, the withstand voltage outer tube 14 of magnetostrictive displacement sensor 1 set up in withstand voltage outer tube appearance chamber 21.

The magnetostrictive displacement sensor 1 is integrated on a sensor support 2 at the tail of an oil cylinder 5 of the rudder pushing mechanism, a waveguide tube carried by the magnetostrictive displacement sensor is arranged in a pressure-resistant outer tube, and the pressure-resistant outer tube is integrally arranged in a sleeve of the sensor support.

The sensor bracket 2 can be fixed with the end cover 3 through a bolt 36 and a mounting screw hole 37 of the sensor bracket 2, on one hand, the sensor bracket 2 plays a role in protecting and supporting the pressure-resistant outer tube 14, on the other hand, the sensor bracket 2 can effectively isolate the oil cylinder accommodating cavity 8 from the pressure-resistant outer tube accommodating cavity 21 through the sleeve 18, so that the magnetostrictive displacement sensor 1 is protected and is not influenced by oil liquid of the oil cylinder; and ensures that the magnetostrictive displacement sensor 1 can be directly detached from the oil cylinder, thereby improving the maintainability.

As shown in fig. 4 and 5, in an embodiment of the non-contact rudder angle feedback mechanism with a built-in cylinder according to the present invention, an external thread 19 is disposed at one end of the pressure-resistant outer tube 14, an internal thread matched with the external thread is disposed in the fixing through hole of the fixing portion 17, and the pressure-resistant outer tube 14 is fixed to the sensor bracket 2 by matching the external thread 19 with the internal thread 20.

As shown in fig. 1 and 6, in an embodiment of the non-contact rudder angle feedback mechanism with a built-in oil cylinder, a sealing groove 22 is circumferentially arranged on a sidewall of a through hole fixing portion 17 of a sensor bracket 2, which is in contact with a through hole of an end cover, and a first sealing ring 23 is arranged in the sealing groove 22;

a second seal ring 24 is circumferentially provided in a gap between the fixing through hole of the fixing portion 17 and the pressure-resistant outer tube 14.

Here, the sensor holder 2 with the magnetostrictive sensor 1 is fixed in the end cover through hole of the end cover 3 by using a bolt, and the joint surface of the sensor holder 2 and the end cover through hole is sealed by using a first seal ring 23. Through the first sealing ring 23 in the sealing groove 22, the gap between the side wall of the through hole fixing part 17 and the end cover through hole can be sealed, and the better sealing of the oil filling cavity 8 is ensured.

In addition, the second sealing ring 24 can fill the gap between the fixing through hole of the fixing part 17 of the sensor holder 2 and the pressure-resistant outer tube 14, thereby further ensuring better sealing of the refueling cavity 8.

Fig. 3 is an enlarged schematic view of the second region 16 in fig. 1, in an embodiment of the non-contact rudder angle feedback mechanism built in an oil cylinder according to the present invention, as shown in fig. 3, a plunger through hole is formed at a tail end 61 of a plunger 6 in an oil filling cavity 8, an annular magnet 4 and a magnetic isolation gasket 7 are arranged on an inner side wall of the plunger through hole, the annular magnet 4 and the magnetic isolation gasket 7 are overlapped, through holes are respectively formed in the annular magnet 4 and the magnetic isolation gasket 7, the through hole of the annular magnet 4, the through hole of the magnetic isolation gasket 7, and the plunger through hole are aligned with each other, wherein the annular magnet 4 is arranged on a side close to an end cover, and the magnetic isolation gasket 7 is arranged on a side far from the end cover;

the sleeve 18 penetrates through the through hole of the annular magnet 4, the through hole of the magnetic isolation gasket 7 and the through hole of the plunger and extends into the cavity 34 of the plunger, and a circumferential gap 27 is reserved between the sleeve 18 and the annular magnet 4.

Here, the ring magnet 4 is embedded in the tail end of the plunger 6, the ring magnet 4 moves along the axial direction 25 of the cylinder synchronously with the plunger 6, and the ring magnet 4 and the waveguide in the magnetostrictive displacement sensor 1 can form a detection loop. A circumferential gap 27 is left between the ring magnet 4 and the sleeve 18 of the sensor carrier 1, so that mechanical friction between the ring magnet 4 and the sleeve 18 during axial movement 25 of the ring magnet is avoided.

The magnetic isolation gasket 7 can be made of nylon materials and has a magnetic isolation effect, the magnetic isolation gasket 7 is embedded between the annular magnet and the plunger 6, and the annular magnet 4 and the magnetic isolation gasket 7 are fixed on the plunger 6 through screws 31.

A circumferential air gap 27 of 7mm is reserved between the annular magnet 4 and the sleeve of the sensor support, so that mechanical friction between the annular magnet 4 and the sleeve in the axial direction 25 moving process driven by the plunger 6 can be avoided. The magnetic isolation gasket 7 is embedded between the annular magnet 4 and the plunger 6 and is sequentially fixed on the plunger 6 through screws. The magnetic isolation gasket 7 is arranged to effectively prevent magnetic conduction.

As shown in fig. 1, in an embodiment of the non-contact rudder angle feedback mechanism with a built-in oil cylinder, the end cover 3 is fixed to an axial direction 25 of the oil cylinder far away from the plunger 6 through a bolt, the end cover 3 is fixed to a radial direction 26 of the oil cylinder far away from the plunger 6 through a snap ring 28, and a fixing collar 30 is sleeved outside the snap ring 28 to further fix the snap ring 28;

and the joint surface of the end cover 3 and the oil cylinder far away from the plunger 6 is sealed 29 by a third sealing ring.

Here, the end cover 3 is axially fixed with the oil cylinder through a bolt, and is radially fixed with the oil cylinder through a snap ring, and the oil cylinder 5 is connected with the base of the ship body through a plurality of groups of bolts, so that the axial or radial displacement between the magnetostrictive displacement sensor 1 and the base can be ignored.

In an embodiment of the non-contact rudder angle feedback mechanism with the built-in oil cylinder, an annular guide liner 32 is arranged on the inner side wall of the oil cylinder 5, the outer side wall of the annular guide liner 32 is in contact with the inner side wall of the oil cylinder, the inner side wall of the annular guide liner 32 is in contact with the outer side wall of the plunger 6, and the guide liner is made of a high-molecular wear-resistant material.

Here, the plunger 6 is inserted into the cylinder along the guide lining, and the high polymer wear-resistant material may be fiber composite, thermosetting resin, or the like. The guide bush can provide support for the plunger 6, so that the plunger 6 can slide on the oil cylinder 5 conveniently, the oil cylinder is prevented from being in direct contact with the plunger 6, and the oil cylinder 5 and the plunger 6 are prevented from being abraded.

By means of the annular guide bush 32, the plunger 6 is moved in the axial direction 25 of the cylinder 5 without movement in the radial direction 26, thereby ensuring the certainty of the direction of movement of the ring magnet 4.

As shown in fig. 1, in an embodiment of the non-contact rudder angle feedback mechanism with a built-in cylinder according to the present invention, a V-shaped combined seal ring is disposed in a gap defined by the guide bush 32, the outer sidewall of the plunger 6, and the inner sidewall of the cylinder 5, and the V-shaped combined seal ring 33 is formed by overlapping a plurality of V-shaped seal rings, and each V-shaped seal ring has a V-shaped cross section.

Here, through forming the V-shaped combination sealing washer 33 together with a plurality of V-shaped sealing washers coincide, can guarantee that the V-shaped combination sealing washer 33 can endure the high-pressure oil pressure in the hydro-cylinder, guarantees the sealed effect of hydro-cylinder.

In addition, a lifting bolt 35 can be arranged on the oil cylinder, so that the oil cylinder is convenient to lift.

In conclusion, the magnetostrictive sensor can realize the function of steering engine rudder angle feedback acquisition;

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

It will be apparent to those skilled in the art that various changes and modifications may be made in the invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. The utility model provides a built-in non-contact rudder angle feedback mechanism of hydro-cylinder which characterized in that includes:

a magnetostrictive displacement sensor comprising: the electronic component is fixed on an oil cylinder outside the oil filling cavity, the electronic component is arranged at the end, far away from the plunger, of the oil cylinder, the waveguide extends into the oil filling cavity, a gap is formed between the waveguide and the annular magnet, and a first magnetic field generated by the waveguide intersects with a second magnetic field generated by the annular magnet to generate a current pulse; the electronic component is used for recording the time period required by the detected current pulse, multiplying the time period by a preset speed to obtain the displacement of the annular magnet and sending the displacement of the annular magnet to the controller;

2. The non-contact rudder angle feedback mechanism with built-in oil cylinder according to claim 1, wherein the magnetostrictive displacement sensor further comprises a pressure-resistant outer pipe, and the waveguide is arranged in a cavity of the pressure-resistant outer pipe.

3. The non-contact rudder angle feedback mechanism built in the oil cylinder according to claim 2, further comprising:

4. The non-contact rudder angle feedback mechanism with a built-in oil cylinder according to claim 3 is characterized in that a sealing groove is circumferentially formed in a side wall of a through hole fixing portion of the sensor bracket which is in contact with the through hole of the end cover, and a first sealing ring is arranged in the sealing groove;

and a second sealing ring is circumferentially arranged in a gap between the fixing through hole of the fixing part and the pressure-resistant outer pipe.

5. The cylinder-embedded non-contact rudder angle feedback mechanism according to claim 1, wherein the electronic components are externally coated with a protective housing.

6. The non-contact rudder angle feedback mechanism arranged in the oil cylinder is characterized in that a plunger through hole is formed in the tail end of the plunger in the oil filling cavity, an annular magnet and a magnetic isolation gasket are arranged on the inner side wall of the plunger through hole, the annular magnet and the magnetic isolation gasket are overlapped, through holes are formed in the annular magnet and the magnetic isolation gasket respectively, the through hole of the annular magnet, the through hole of the magnetic isolation gasket and the plunger through hole are aligned with each other, the annular magnet is arranged on the side close to the end cover, and the magnetic isolation gasket is arranged on the side far away from the end cover;

7. The non-contact rudder angle feedback mechanism with a built-in oil cylinder as claimed in claim 3 is characterized in that the end cover is axially fixed with the oil cylinder far away from the plunger end through a bolt, the end cover is radially fixed with the oil cylinder far away from the plunger end through a snap ring, and a fixing lantern ring is sleeved outside the snap ring.

8. The non-contact rudder angle feedback mechanism with an inside cylinder as claimed in claim 3, wherein the joint surface of the end cover and the cylinder far away from the plunger end is sealed by a third sealing ring.

9. The non-contact rudder angle feedback mechanism with built-in oil cylinder according to claim 1 is characterized in that an annular guide bush is arranged on the inner side wall of the oil cylinder, the outer side wall of the annular guide bush is in contact with the inner side wall of the oil cylinder, the inner side wall of the annular guide bush is in contact with the outer side wall of the plunger, and the guide bush is made of high-molecular wear-resistant material.

10. The non-contact rudder angle feedback mechanism with an internal cylinder according to claim 9 is characterized in that a V-shaped combined sealing ring is arranged in a gap defined by the guide bush, the outer side wall of the plunger and the inner side wall of the cylinder, wherein the V-shaped combined sealing ring is formed by overlapping a plurality of V-shaped sealing rings, and the cross section of each V-shaped sealing ring is V-shaped.