Oil pressure resistant servo valve sensor with spring

Abstract

The invention relates to an oil-pressure-resistant servo valve sensor with a spring, and belongs to the technology of differential linear displacement sensors. The sensor comprises a coil, a shell, a spring, a lining, an iron core connecting rod, a cover plate and a clamping ring. The shell is a cylindrical shell with a stator cavity and a spring cavity, the stator cavity is located in the spring cavity, and the coil is installed in the stator cavity; a shell step and a clamping ring groove are arranged on the inner wall of the spring cavity in the circumferential direction, a clamping ring is installed in the clamping ring groove, and a spring is installed in the spring cavity. The thin end of the spring cavity and the stator cavity share one part of the shell, the lining is installed in the stator cavity, the iron core connecting rod is installed in the lining, and the cover plate is installed in the thick end of the spring cavity. One end face of the cover plate leans against the spring, and the other end face is limited by the retainer ring.

Description

Technical Field

[0001] This invention belongs to the field of differential linear displacement sensor technology, specifically relating to a hydraulically resistant servo valve sensor with a built-in spring. Background Technology

[0002] The servo valve sensor is a differential linear displacement sensor that uses the principle of a non-contact differential transformer. Its main structure consists of two parts: a stator and an iron core. The stator contains an excitation winding and an output winding, while the iron core is a simple magnetic conductor. Due to the mutual inductance between the excitation and output windings, the linear mechanical displacement of the iron core is converted into a voltage signal proportional to it.

[0003] Typical solutions adopted for servo valve sensors include: Figure 1 As shown, the sensor stator and core are separate structures. The servo valve core, under the spring force of the servo valve spring, pushes the sensor core to produce linear motion. This scheme has the following main drawbacks: 1) The separate stator and core structure need to be installed separately on the servo valve, making the coaxiality alignment process complex; 2) The sensor cannot achieve pressure resistance independently and can only achieve pressure resistance together with the servo valve, increasing verification costs; 3) The structure where the sensor core, servo valve core, and spring are in a straight line occupies a large axial space, resulting in a large servo valve size and weight. Summary of the Invention

[0004] The purpose of this invention is to address the problems of incomplete functionality of traditional servo valve sensors, high assembly complexity of servo valves, and large size and weight of servo valves, and to propose a hydraulically resistant servo valve sensor with a built-in spring.

[0005] Technical solution: A hydraulically resistant servo valve sensor with a built-in spring includes: a housing 1, a coil 2, a spring 3, a bushing 4, an iron core connecting rod 5, a cover plate 6, and a retaining ring 7. The outer shell is a cylindrical shell with a stator cavity 8 and a spring cavity 9. The stator cavity 8 is located inside the spring cavity 9, and a stator step 12 is provided circumferentially on the inner wall of the stator cavity 8. The coil 2 is installed in the stator cavity 8. The inner wall of the spring cavity 9 is provided circumferentially with an outer shell step 10 and a retaining ring groove 11. The retaining ring 7 is installed in the retaining ring groove 11, and the spring 3 is installed in the spring cavity 9. The thin end of the spring cavity 9 shares a portion of the shell with the stator cavity 8. The cover plate 6 is installed inside the thick end of the spring cavity 9 and is coaxial with the thick end of the spring cavity 9.

[0006] Furthermore, the bushing 4 is an annular cylinder with a bushing cover 13 and a bushing inner hole 15. The left end face of the bushing cover 13 rests on the stator step 12, and the narrow end of the bushing 4 is inserted into the stator cavity 8.

[0007] Furthermore, a cover plate circular hole 14 along its own axis is opened on the cover plate 6. The core connecting rod 5 is installed into the bushing inner hole 15 and the cover plate circular hole 14, and is coaxial with the stator step 12 and the cover plate circular hole 14.

[0008] Furthermore, the cover plate circular hole 14 is provided with a cover plate step 16 along the circumference, and the iron core connecting rod 5 rests on the surface of the cover plate step 16.

[0009] Furthermore, one side of the end face of the cover plate 6 rests against the spring 3, and the other side is limited by the retaining ring 7. An oil drain hole 17 is opened on the end face of the cover plate 6.

[0010] Furthermore, the wall thickness of the spring cavity 9 and the bushing inner hole 15 is not less than 0.7 mm.

[0011] Furthermore, the diameter of the oil drain hole 17 is not less than 2mm.

[0012] Furthermore, the outer circle of the bushing cover 13 and the inner circle of the stator step 12 are fastened together by circumferential welding.

[0013] Furthermore, the bushing inner hole 15 and the spring cavity 9 need to withstand oil pressure.

[0014] The working principle of a spring-loaded oil-pressure servo valve sensor is as follows: when the servo valve spool moves towards the sensor, it pushes the sensor cover plate and connecting rod core to a compressed position, compressing the sensor spring. When the servo valve spool retracts, the spring pushes the cover plate and connecting rod core back to the sensor's initial position, thus resetting the sensor. During this process, the sensor converts the linear mechanical displacement of the core and connecting rod into a proportional voltage signal, thereby converting the valve spool position into a proportional voltage signal.

[0015] The beneficial effects of this invention are as follows: This invention proposes a spring-integrated oil-pressure resistant servo valve sensor, achieving for the first time a pressure-resistant servo valve sensor independently realizing complete functionality. The advantages of this spring-integrated oil-pressure resistant servo valve sensor are: through the integrated sensor structure and welded connection structure design, it achieves independent oil-pressure resistance while effectively simplifying the assembly difficulty of the servo valve; simultaneously, by embedding the spring within the sensor, it saves axial space and reduces weight in the servo valve, thus meeting the production efficiency requirements of servo valve sensors in mass production. This spring-integrated oil-pressure resistant servo valve sensor structure is applied to servo valve sensors used in civil aircraft for monitoring the position of the servo valve core. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a cross-sectional view of a typical servo valve sensor. Figure 2 This is a cross-sectional view of an oil pressure servo valve sensor with an integrated spring according to the present invention. Figure 3 This is a cross-sectional view of the housing of a hydraulically resistant servo valve sensor with an integrated spring, according to the present invention. Figure 4 This is a cross-sectional view of the bushing of a spring-loaded oil pressure servo valve sensor according to the present invention. Figure 5 This is a three-dimensional schematic diagram of the cover plate of a hydraulically resistant servo valve sensor with an integrated spring according to the present invention. Wherein, 1: outer shell, 2: coil, 3: spring, 4: bushing, 5: core connecting rod, 6: cover plate, 7: retaining ring, 8: stator cavity, 9: spring cavity, 10: outer shell step, 11: retaining ring groove, 12: stator step, 13: bushing cover, 14: cover plate round hole, 15: bushing inner hole, 16: cover plate step, 17: oil drain hole. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0020] In the description of this invention, it should be noted that the directions or positional relationships indicated by terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing and simplifying the invention, and should not be construed as limiting the invention. Furthermore, the use of ordinal numbers (e.g., "first and second," etc.) is for distinguishing objects and is not limited to this order, and should not be construed as indicating or implying relative importance.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly, encompassing both direct connection and indirect connection via an intermediate medium. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0022] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0024] Figure 2 The present invention provides an oil pressure servo valve sensor with a built-in spring, comprising a housing 1, a coil 2, a spring 3, a bushing 4, an iron core connecting rod 5, a cover plate 6, and a retaining ring 7.

[0025] Figure 3 This is a cross-sectional view of the housing 1 of a hydraulic servo valve sensor with a built-in spring according to the present invention. The housing 1 is a cylindrical shell with a stator cavity 8 and a spring cavity 9. The stator cavity 8 is located inside the spring cavity 9. The inner wall of the spring cavity 9 is provided with a housing step 10 and a retaining ring groove 11 along the circumferential direction. The thin end of the spring cavity 9 shares a portion of the housing with the stator cavity 8. The inner wall of the stator cavity 9 is provided with a stator step 12 along the circumferential direction.

[0026] Figure 4 This is a cross-sectional view of the bushing 4 of a hydraulic servo valve sensor with a built-in spring according to the present invention. The bushing 4 is an annular cylinder with a bushing cover 13 and a bushing inner hole 15. The left end face of the bushing cover 13 rests on the stator step 12, and the thin end of the bushing is inserted into the stator cavity 8. The bushing cover 13 and the stator cavity 8 are fastened together by circumferential welding.

[0027] Figure 5This is a three-dimensional schematic diagram of the cover plate 6 of a hydraulic servo valve sensor with a built-in spring according to the present invention. The cover plate 6 has a cover plate circular hole 14 along its own axis. The cover plate 6 is installed inside the thick end of the spring cavity 9 and is coaxial with the thick end of the spring cavity 9. The cover plate circular hole 14 is provided with a cover plate step 16 in the circumferential direction. An oil drain hole 17 is opened on the end face of the cover plate 6. The diameter of the oil drain hole 17 is not less than 2mm.

[0028] The coil 2 is installed in the stator cavity 8; the retaining ring 7 is installed in the retaining ring groove 11; the spring 3 is installed in the spring cavity 9; the core connecting rod 5 is inserted into the bushing inner hole 15 and the cover plate round hole 14, rests on the cover plate step surface 16, and is coaxial with the stator step 12 and the cover plate round hole 14; one end face of the cover plate 6 rests on the spring 3, and the other end is limited by the retaining ring 7.

[0029] Based on the above embodiments, as an optional embodiment, the diameter of the oil drain hole 17 on the cover plate 6 is 2.5mm. Furthermore, when the cover plate 6 compresses the spring 3 and moves towards the stator cavity 8, four axially evenly distributed oil drain holes 17 are used to better discharge the hydraulic oil from the spring cavity 9.

[0030] Based on the above embodiments, as an optional embodiment, in order to enable the sensor to withstand a pressure of 21MPa for more than 1 minute, the thinnest part of the wall thickness of the spring cavity 9 and the inner hole of the bushing 15 is 0.75mm, and the outer circle of the bushing cover 13 and the inner circle of the stator step 12 of the outer shell are fastened by circumferential welding, with a weld depth of more than 1.5mm.

[0031] The above detailed embodiments are a description of the present invention. It should not be considered that the specific embodiments of the present invention are limited to these descriptions. For those skilled in the art, several simple deductions and substitutions can be made without departing from the concept of the present invention, and all of these should be considered to fall within the protection scope of the present invention.

Claims

1. A hydraulically resistant servo valve sensor with a built-in spring, characterized in that, The sensor includes: housing (1), coil (2), spring (3), bushing (4), iron core connecting rod (5), cover plate (6), and retaining ring (7); The outer shell is a cylindrical shell with a stator cavity (8) and a spring cavity (9). The stator cavity (8) is located inside the spring cavity (9). The inner wall of the stator cavity (8) is provided with a stator step (12) along the circumferential direction. The coil (2) is installed in the stator cavity (8). The inner wall of the spring cavity (9) is provided with an outer shell step (10) and a retaining ring groove (11) along the circumferential direction. The retaining ring (7) is installed in the retaining ring groove (11). The spring (3) is installed in the spring cavity (9). The thin end of the spring cavity (9) shares a part of the shell with the stator cavity (8). The cover plate (6) is installed inside the thick end of the spring cavity (9) and is coaxial with the thick end of the spring cavity (9).

2. The oil-pressure resistant servo valve sensor with built-in spring according to claim 1, characterized in that, The bushing (4) is an annular cylinder with a bushing cover (13) and a bushing inner hole (15). The left end face of the bushing cover (13) rests on the stator step (12), and the narrow end of the bushing (4) is inserted into the stator cavity (8).

3. A hydraulically resistant servo valve sensor with a built-in spring according to claim 2, characterized in that, The cover plate (6) has a cover plate circular hole (14) along its own axis. The core connecting rod (5) is installed in the bushing inner hole (15) and the cover plate circular hole (14), and is coaxial with the stator step (12) and the cover plate circular hole (14).

4. A hydraulically resistant servo valve sensor with a built-in spring according to claim 3, characterized in that, The cover plate round hole (14) is provided with a cover plate step (16) along the circumference, and the iron core connecting rod (5) rests on the surface of the cover plate step (16).

5. A hydraulically resistant servo valve sensor with a built-in spring according to claim 3, characterized in that, One side of the end face of the cover plate (6) rests against the spring (3), and the other side is limited by the retaining ring (7). An oil drain hole (17) is opened on the end face of the cover plate (6).

6. The oil pressure resistant servo valve sensor with built-in spring as described in claim 1 is characterized in that, The wall thickness of the spring cavity (9) and the bushing inner hole (15) is not less than 0.7 mm.

7. A hydraulically resistant servo valve sensor with a built-in spring according to claim 5, characterized in that, The diameter of the oil drain hole (17) is not less than 2mm.

8. A hydraulically resistant servo valve sensor with a built-in spring according to claim 2, characterized in that, The outer circle of the bushing cover (13) and the inner circle of the stator step (12) are fastened together by welding around the circumference.

9. A hydraulically resistant servo valve sensor with an integrated spring according to claim 1, characterized in that, The bushing bore (15) and spring cavity (9) need to withstand oil pressure.

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