A unidirectional linear electromagnetic drive mechanism

Abstract

This invention relates to the field of linear electromagnetic drive mechanism technology, and discloses a unidirectional linear electromagnetic drive mechanism. The outer shell is a cylindrical structure open at one end. A rear cover is located at the bottom of the second-stage step hole of the outer shell, and a convex cylindrical protrusion of the rear cover is located within the third-stage step hole of the outer shell. One end of the shaft extends into the bottom of the second-stage step hole of the rear cover, and a linear bearing is provided in the first-stage step hole of the rear cover to support the shaft. The pole shoe end cover is a cylinder with a shaft through hole. The moving iron core and the pole shoe end cover are located inside the outer shell and sleeved on the shaft. A bushing is fixed to the outer surface of the rear cover, and one end of the bushing extends to the area where the moving iron core is located. One end of the magnetic isolation shoe has an outer annular step that concentrically connects with the inner annular step of the bushing. One side of the pole shoe end cover has an outer annular inclined surface that connects with the inner annular inclined surface of the magnetic isolation shoe. The other side of the pole shoe end cover has a bearing chamber for installing a linear bearing to support the shaft. The winding is wound on the frame, and the frame is fixed to the outer surface of the pole shoe end cover.

Description

Technical Field

[0001] This invention relates to the field of linear electromagnetic drive mechanism technology, and in particular to a unidirectional linear electromagnetic drive mechanism. Background Technology

[0002] In the field of modal switching valves, there is a demand for linear electromagnetic drive mechanisms that are resistant to oil pressure, have long strokes, and high initial thrust. Traditional linear electromagnetic drive mechanisms for valves have short strokes. If the stroke is increased, the air gap needs to be increased significantly, which will lead to a sharp decrease in initial thrust. Low initial thrust is difficult to overcome hydraulic loads and spring loads, and the anti-interference ability will also be weakened. If the initial thrust is to be increased, the size and weight will be increased significantly, which is difficult to meet the application requirements. Summary of the Invention

[0003] The purpose of this invention is to propose a hydraulically resistant, high-initial-thrust unidirectional linear electromagnetic drive mechanism. This structure has a large working air gap and incorporates a pole shoe structure in the magnetic circuit. When current is applied to the winding, in the initial position, most of the generated magnetic flux flows through the pole shoe structure, causing the moving iron core to experience an axial tangential force, thereby increasing the initial thrust of the moving iron core. As the moving iron core moves, due to the magnetic saturation effect of the pole shoe structure, its magnetic flux remains essentially constant, thus maintaining a constant thrust until the final stroke, when the thrust increases sharply. To achieve full-stroke drive functionality, linear bearings are installed at both ends to ensure concentric linear motion of the moving iron core. Simultaneously, the moving iron core operates in oil, and oil pressure balance at both ends is achieved through oil passages. To ensure normal function under high oil pressure, a full seal is achieved through sealing rings and vacuum brazing to prevent oil leakage. This results in a unidirectional linear electromagnetic drive mechanism with high initial thrust and high oil pressure resistance. Compared to traditional linear electromagnetic drive mechanisms with the same stroke, this new mechanism can increase the initial thrust tenfold, and the oil pressure can withstand up to 35 MPa.

[0004] A unidirectional linear electromagnetic drive mechanism includes: a fixed housing, windings, pole shoe end caps, magnetic isolation shoes, a frame, bushings, a moving iron core, a shaft, a rear cover, and two linear bearings;

[0005] The outer shell is a cylindrical structure with one end open, and the interior has three stepped holes with the diameter decreasing from the open end to the bottom.

[0006] The rear cover is located at the bottom of the second-level step hole of the outer shell. The rear cover is a "convex" cylinder. The protruding part of the "convex" cylinder of the rear cover is located in the third-level step hole of the outer shell. The rear cover has two levels of step holes inside, and the opening end is located on the side away from the "convex" cylinder.

[0007] One end of the shaft extends into the bottom of the second-stage step hole of the rear cover, and a linear bearing is provided in the first-stage step hole of the rear cover to support the shaft.

[0008] The pole shoe end cap is a cylinder with a shaft through hole. The moving iron core and the pole shoe end cap are located inside the outer shell and are sleeved on the shaft. The moving iron core is located between the rear cover and the pole shoe end cap.

[0009] The bushing is fixed to the outer surface of the rear cover, and one end of the bushing extends to the area where the moving iron core is located. The inner surface of the bushing near the moving iron core is provided with an inner annular step.

[0010] The magnetic isolation shoe is a ring-shaped component. One end is provided with an outer ring step that is concentrically connected to the inner ring step of the bushing. The other end of the magnetic isolation shoe is provided with an inner ring slope. The pole shoe end cap is provided with an outer ring slope on the side near the moving iron core, which is connected to the inner ring slope of the magnetic isolation shoe.

[0011] The pole shoe end cap has a bearing chamber on the side away from the moving iron core for installing linear bearings to support the shaft;

[0012] The skeleton is a cylindrical shape with outer annular edges at both ends. After the winding is wound on the skeleton, the skeleton is fixed between the outer surface of the pole shoe end cap and the first-stage step hole of the outer shell.

[0013] Furthermore, the outer surface of the rear cover is provided with an annular groove, and a sealing ring is provided in the annular groove to seal the gap between the rear cover and the bushing.

[0014] Furthermore, the outer annular inclined surface of the pole shoe end cap and the magnetic isolation shoe, as well as the inner annular step of the magnetic isolation shoe and the bushing, are respectively fixed together by vacuum brazing.

[0015] Furthermore, one end of the outer annular inclined surface of the pole shoe end cap is provided with a blind hole coaxial with the shaft, the depth of the blind hole being equal to the length of the annular inclined surface, ranging from 5mm to 20mm; the diameter of the blind hole is clearance-fitted with the outer diameter of the moving iron core.

[0016] When one end of the moving iron core is tightly attached to the back cover, the other end of the moving iron core is flush with the opening end of the blind hole.

[0017] Furthermore, the outer shell, pole shoe end cap, moving iron core, and bushing are made of magnetically conductive materials; the magnetically shielding shoe, rear cover, and shaft are made of non-magnetically conductive metal materials; and the frame is made of non-magnetically conductive metal materials with its outer surface insulated.

[0018] Furthermore, the moving iron core is connected to the shaft by a thread.

[0019] Furthermore, the shaft is provided with an annular platform in the region of the moving iron core, and the moving iron core cooperates with the annular platform to drive the shaft to move and limit its position.

[0020] Furthermore, the moving iron core is provided with two axial oil passage holes.

[0021] Furthermore, the bottom of the outer casing is provided with a groove perpendicular to the axial direction of the stepped hole in the outer casing. The bottom of the groove is connected to the bottom of the first-stage stepped hole. A socket is provided in the groove, and the socket is connected to the winding through a wire.

[0022] Beneficial effects

[0023] This invention proposes a high-initial-thrust unidirectional linear electromagnetic drive mechanism with high oil pressure resistance. This structure features a large working air gap and a pole shoe structure in the magnetic circuit. When current is applied to the winding, at the initial position, most of the generated magnetic flux flows through the pole shoe structure, subjecting the moving iron core to an axial tangential force, thus increasing the initial thrust of the moving iron core. As the moving iron core moves, due to the magnetic saturation effect of the pole shoe structure, its magnetic flux remains essentially constant, thus maintaining a constant thrust until the final stroke, at which point the thrust increases dramatically, achieving full-stroke drive functionality. Simultaneously, the moving iron core operates in oil, with oil pressure balance at both ends achieved through an oil passage. To ensure normal function under high oil pressure, a sealing ring and vacuum brazing are used to achieve a complete seal, preventing oil leakage. This results in a high-initial-thrust unidirectional linear electromagnetic drive mechanism with high oil pressure resistance. Compared to traditional linear electromagnetic drive mechanisms of the same stroke, this novel mechanism can increase the initial thrust tenfold, and the oil pressure can withstand up to 35 MPa. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, 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.

[0025] Figure 1 This is a schematic diagram of a hydraulically resistant, high-initial-thrust, unidirectional linear electromagnetic drive mechanism.

[0026] Among them, 1: fixed shell, 2: winding, 3: pole shoe end cover, 4: magnetic isolation shoe, 5: bushing, 6: rear cover, 7: moving iron core, 8: shaft, 9: sealing ring, 10: linear bearing, 11: frame, 12: socket;

[0027] Figure 2 It is a three-dimensional schematic diagram of the fixed outer shell;

[0028] Figure 3 It is a three-dimensional schematic diagram of the moving iron core;

[0029] Figure 4 This is a magnetic field cloud diagram when the initial position is energized;

[0030] Figure 5 This is the magnetic field cloud diagram at the maximum position;

[0031] Figure 6 It is a graph showing the changes in electromagnetic force and load spring force with displacement. Detailed Implementation

[0032] 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.

[0033] 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.

[0034] 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.

[0035] like Figure 1 , 2 As shown, a unidirectional linear electromagnetic drive mechanism with high initial thrust and oil pressure resistance includes a fixed housing 1, a winding 2, a pole shoe end cover 3, a magnetic isolation shoe 4, a bushing 5, a rear cover 6, a moving iron core 7, a shaft 8, a sealing ring 9, two linear bearings 10, a frame 11, and a socket 12.

[0036] The fixed housing 1 is a U-shaped cylindrical structure with a groove at one end and a stepped cavity inside. The winding 2 is made of high-temperature resistant enameled copper wire, wound in several turns on the frame 11 and concentrically installed in the cavity of the fixed housing 1. The socket 12 is a socket with three pins, concentrically installed on the end face of the groove of the fixed housing 1. The rear cover 6 is a cavity structure with one closed end, its closed end installed at the bottom of the cavity of the fixed housing 1. Its radial outer surface has a sealing groove, and the sealing ring 9 is made of high-temperature resistant fluorosilicone rubber material and installed in the sealing groove. The radial inner surface has a bearing chamber, and a linear bearing 10 with two rows of high-hardness balls is installed in the bearing chamber. The bushing 5 is a cylindrical structure with a step at one end, which is concentrically installed in the cavity of the fixed housing 1. The core is mounted on the outer surface of the back cover 6; the magnetic isolation shoe 4 is a cylindrical structure with a step at one end and a slope at the other end, with its stepped end concentrically connected to the stepped end of the bushing 5; the pole shoe end cap 3 is a hollow stepped cylindrical structure with a pole shoe at one end, the pole shoe being 5mm long, with its pole shoe end concentrically connected to the slope of the magnetic isolation shoe 4; the connection between the pole shoe end cap 3, the magnetic isolation shoe 4, and the bushing 5 is achieved through vacuum brazing; the other end of the pole shoe end cap 3 has a stepped groove, with a bearing chamber at the bottom of the groove, and a linear bearing 10 with two rows of high-hardness balls is installed in the bearing chamber; the shaft 10 is a slender rod-like structure that passes through two linear bearings 10; the moving iron core 7 is a hollow cylindrical structure with two oil passages, such as... Figure 3 As shown, it is connected and installed on one side of shaft 10 via threads; wherein, the fixed outer shell 1, pole shoe end cover 3, bushing 5, and moving iron core 7 are made of soft magnetic alloy material, specifically 1J50 soft magnetic alloy material; the magnetic isolation shoe 4 and shaft 8 are made of austenitic stainless steel for antimagnetic treatment, the rear cover 6 is made of titanium alloy material, the frame 11 is made of titanium alloy material, and the surface is sprayed with insulating material. In the initial position, the moving iron core 7 is close to the end face of the opening of the rear cover 6, and when it moves to the maximum position, the moving iron core 7 is close to the bottom end face of the pole shoe end groove of the pole shoe end cover 3.

[0037] The working principle of the oil-pressure resistant, high initial thrust unidirectional linear electromagnetic drive mechanism of the present invention is as follows: Figure 1 The energized winding generates an electrically excited magnetomotive force, which always closes along the path of least magnetic reluctance. In the initial position, such as... Figure 4 As shown, the magnetic field passes through the fixed shell, bushing, and moving iron core. A portion passes through the pole shoes (end caps), while the other portion passes directly through the air gap. Finally, it returns to the fixed shell through the pole shoe end caps to close the magnetic field. Due to the presence of the pole shoes, a portion of the magnetic flux flows through them, and the moving iron core experiences an axial electromagnetic force. Because the pole shoes are relatively small compared to the magnetically conductive parts, they are always in a saturated state within a certain stroke. Within this range, the electromagnetic force remains essentially constant, depending entirely on the current magnitude. The moving iron core, subjected to the axial electromagnetic force, overcomes the load and produces linear motion. When it reaches its maximum position, as... Figure 5As shown, at this point, the pole shoes no longer function. Since the air gap is very small, the magnetic field flows directly from the moving iron core to the pole shoe end cap, and the electromagnetic force reaches its maximum value. The moving iron core is fully attracted. At this point, a very small current is sufficient to ensure that the moving iron core has a large attraction force, thus overcoming the spring load and hydraulic force. The high-pressure oil inside flows in from the groove in the pole shoe end cap, passes through the oil passage in the moving iron core, and reaches the groove in the rear cover. Because the rear cover has a sealing ring, and the pole shoe end cap, magnetic isolation shoe, and bushing are vacuum brazed together, they are sealed. The high-pressure oil is enclosed in the cavity where the moving iron core is located, achieving unidirectional linear motion of the moving iron core with high initial thrust under high oil pressure. The relationship between the electromagnetic force and displacement throughout its entire stroke is shown in [reference needed]. Figure 6 As shown, within a certain range of travel, its electromagnetic force remains basically unchanged.

[0038] This invention proposes a high-initial-thrust unidirectional linear electromagnetic drive mechanism with high oil pressure resistance. This structure features a large working air gap and a pole shoe structure in the magnetic circuit. When current is applied to the winding, at the initial position, most of the generated magnetic flux flows through the pole shoe structure, subjecting the moving iron core to an axial tangential force, thus increasing the initial thrust of the moving iron core. As the moving iron core moves, due to the magnetic saturation effect of the pole shoe structure, its magnetic flux remains essentially constant, thus maintaining a constant thrust until the final stroke, at which point the thrust increases dramatically, achieving full-stroke drive functionality. Simultaneously, the moving iron core operates in oil, with oil pressure balance at both ends achieved through an oil passage. To ensure normal function under high oil pressure, a sealing ring and vacuum brazing are used to achieve a complete seal, preventing oil leakage. This results in a high-initial-thrust unidirectional linear electromagnetic drive mechanism with high oil pressure resistance. Compared to traditional linear electromagnetic drive mechanisms of the same stroke, this novel mechanism can increase the initial thrust tenfold, and the oil pressure can withstand up to 35 MPa.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. A unidirectional linear electromagnetic drive mechanism, characterized in that, The mechanism includes: a fixed outer shell, windings, pole shoe end caps, magnetic isolation shoes, a frame, bushings, a moving iron core, a shaft, a rear cover, and two linear bearings; The outer shell is a cylindrical structure with one end open, and the interior has three stepped holes with the diameter decreasing from the open end to the bottom. The rear cover is located at the bottom of the second-level step hole of the outer shell. The rear cover is a "convex" cylinder. The protruding part of the "convex" cylinder of the rear cover is located in the third-level step hole of the outer shell. The rear cover has two levels of step holes inside, and the opening end is located on the side away from the "convex" cylinder. One end of the shaft extends into the bottom of the second-stage step hole of the rear cover, and a linear bearing is provided in the first-stage step hole of the rear cover to support the shaft. The pole shoe end cap is a cylinder with a shaft through hole. The moving iron core and the pole shoe end cap are located inside the outer shell and are sleeved on the shaft. The moving iron core is located between the rear cover and the pole shoe end cap. The moving iron core is provided with two axial oil passage holes. The bushing is fixed to the outer surface of the rear cover, and one end of the bushing extends to the area where the moving iron core is located. The inner surface of the bushing near the moving iron core is provided with an inner annular step. The magnetic isolation shoe is an annular component. One end has an outer annular step that concentrically connects with the inner annular step of the bushing. The other end of the magnetic isolation shoe has an inner annular inclined surface. The pole shoe end cap has an outer annular inclined surface on the side near the moving iron core that connects with the inner annular inclined surface of the magnetic isolation shoe. One end of the outer annular inclined surface of the pole shoe end cap has a blind hole coaxial with the shaft. The depth of the blind hole is equal to the length of the annular inclined surface, which is 5mm to 20mm. The diameter of the blind hole is clearance-fitted with the outer diameter of the moving iron core. When one end of the moving iron core is tightly attached to the rear cover, the other end of the moving iron core is flush with the opening end of the blind hole. The pole shoe end cap has a bearing chamber on the side away from the moving iron core for installing linear bearings to support the shaft; The skeleton is a cylindrical shape with outer annular edges at both ends. After the winding is wound on the skeleton, the skeleton is fixed between the outer surface of the pole shoe end cap and the first-stage step hole of the outer shell.

2. The mechanism according to claim 1, characterized in that, The outer surface of the rear cover is provided with an annular groove, and a sealing ring is provided in the annular groove to seal the gap between the rear cover and the bushing.

3. The mechanism according to claim 1, characterized in that, The outer annular inclined surface of the pole shoe end cap and the magnetic isolation shoe, and the inner annular step of the magnetic isolation shoe and the bushing are respectively fixed together by vacuum brazing.

4. The mechanism according to claim 1, characterized in that, The outer shell, pole shoe end cap, moving iron core, and bushing are made of magnetically conductive materials; the magnetic isolation shoe, rear cover, and shaft are made of non-magnetically conductive metal materials; the frame is made of non-magnetically conductive metal materials and its outer surface is insulated.

5. The mechanism according to claim 1, characterized in that, The moving iron core is connected to the shaft by a thread.

6. The mechanism according to claim 5, characterized in that, The shaft is located in the area of ​​the moving iron core and has an annular platform. The moving iron core and the annular platform cooperate to drive the shaft to move and limit its movement.

7. The mechanism according to claim 1, characterized in that, The bottom of the outer casing is also provided with a groove perpendicular to the axial direction of the stepped hole in the outer casing. The bottom of the groove is connected to the bottom of the first-stage stepped hole. A socket is provided in the groove, and the socket is connected to the winding through a wire.

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