A new type of electromagnetic actuator

Abstract

The purpose of the present invention is to provide a new type of electromagnetic actuator, including an outer cylinder, an upper end cover and a lower end cover are installed at the upper and lower ends of the outer cylinder respectively, a shaft, a magnetizer and a permanent magnet are arranged in the space formed by the upper end cover, the outer cylinder and the lower end cover, the upper and lower ends of the shaft are respectively fixedly connected with the upper end cover and the lower end cover, the outer end of the shaft is installed with a magnetizer with an H-shaped cross section, a graphite copper sleeve is installed between the magnetizer and the shaft, a permanent magnet is installed in the groove of the H-shaped cross section of the magnetizer, an air gap is formed between the permanent magnet and the inner side of the groove, a coil frame is installed in the air gap, a winding coil is wound on the coil frame, and mechanical springs are respectively sleeved at the upper and lower ends of the shaft, and the mechanical springs are respectively pressed between the upper end cover and the magnetizer and between the lower end cover and the magnetizer. As an actuator, the present invention generates a reciprocating force that changes with the current in a constant magnetic field by applying a current of a certain frequency to the winding coil, causing the mover to reciprocate along the shaft, thereby generating the required inertial force and outputting it to the outside.

Description

Technical Field

[0001] The present invention relates to an actuator for active vibration control, in particular to an electromagnetic actuator. Background Art

[0002] Traditional passive vibration isolation or vibration absorption is limited by narrow frequency band and low efficiency, and it is difficult to meet the increasing vibration reduction requirements. Active control technology has strong adaptability and a wide controllable frequency band, which makes up for the shortcomings of passive vibration isolation.

[0003] The difficulty of active control research lies in control technology and actuators. As a structure that receives instructions and applies force, the actuator is the key to the practical application of active control. Electromagnetic actuators are widely used in many industries due to their advantages such as no contact friction, rapid response, and large control force.

[0004] For existing electromagnetic actuators, such as patent CN206416898U, the electromagnet principle is used, which is limited by the size of the iron core, resulting in problems such as insufficient compactness and excessive size. There are also problems such as CN110027587A due to the relatively narrow magnetic circuit design, such as leakage magnetic flux and small electromagnetic force coefficient. Or the mover designed by CN107781339B lacks axial constraints, and there will be eccentricity problems during movement. Most actuators such as CN104976263A, CN107781339B, etc., usually rely on the reed structure to provide internal support force in order to make the structure compact. This type of design will lack reliability in long-term work and is not ideal in actual engineering applications. Summary of the invention

[0005] The object of the present invention is to provide a novel electromagnetic actuator with the advantages of compact structure, reasonable magnetic circuit design, high magnetic energy utilization rate, high reliability, low energy consumption, etc.

[0006] The object of the present invention is achieved in that:

[0007] The invention discloses a novel electromagnetic actuator, which is characterized in that it comprises an outer cylinder, an upper end cover and a lower end cover are respectively installed at the upper and lower ends of the outer cylinder, a shaft, a magnetizer and a permanent magnet are arranged in a space formed by the upper end cover, the outer cylinder and the lower end cover, the upper and lower ends of the shaft are respectively fixedly connected to the upper end cover and the lower end cover, the outer portion of the shaft is installed with a magnetizer with an H-shaped cross section, a graphite copper sleeve is installed between the magnetizer and the shaft, a permanent magnet is installed in a groove with an H-shaped cross section of the magnetizer, an air gap is formed between the permanent magnet and the inner side of the groove, a coil frame is installed in the air gap, a winding coil is wound on the coil frame, the upper and lower ends of the shaft are respectively sleeved with mechanical springs, and the mechanical springs are respectively pressed between the upper end cover and the magnetizer and between the lower end cover and the magnetizer.

[0008] The present invention may also include:

[0009] 1. Limiting nuts are sleeved on the shafts at both ends of the graphite copper sleeve. The graphite copper sleeve is attached to the magnetic conductor and fixed by the limiting nuts to form a stator.

[0010] 2. The permanent magnet has a tile-like structure. The permanent magnets are attached to each other to form a ring structure. The permanent magnets are radially magnetized and the magnetization direction is consistent.

[0011] 3. The outer surface of the limit nut has an external thread connected to the magnetic conductor, and a groove is provided at one end of the limit nut close to the upper end cover and the lower end cover.

[0012] 4. Two recesses are provided inside the magnetic conductor, which are used to cooperate with the limit nut to fix the graphite sleeve and install the spring respectively. The recess near the center is provided with an internal thread.

[0013] 5. The upper end cover and the lower end cover are provided with countersunk holes and bosses. The countersunk holes are located between the upper end cover and the lower end cover to clamp the shaft and are fixedly connected by screws. The bosses are assembled and fixed to the mechanical spring position.

[0014] 6. The coil frame is connected to the outer sides of the upper end cover and the lower end cover bosses by means of screws.

[0015] 7. The magnetic conductor is made of electromagnetic soft iron.

[0016] 8. The gap between the coil frame and the permanent magnet is 0.5-1.5mm, and the gap between the coil frame and the inner side of the magnet groove is 1-2mm.

[0017] The advantages of the present invention are:

[0018] 1. The electromagnetic actuator of the present invention uses an integrated magnetic conductor design to make the overall structure of the mover simpler, more compact and easier to assemble, while limiting the overall volume while ensuring the quality of the mover, which can meet the output effect of the actuator with high power density;

[0019] 2. The magnetizer has an "H"-shaped symmetrical structure. The upper and lower magnetic circuits formed effectively alleviate the problem of easy magnetic saturation of single-circuit magnetizers. At the same time, the thick cross-section of the magnetizer constructs a wide magnetic circuit, which greatly reduces magnetic leakage;

[0020] 3. The tile-shaped permanent magnet adopts radiation magnetization, and the air gap structure design adjacent to the permanent magnet improves the utilization rate of magnetic energy;

[0021] 4. The use of graphite copper sleeve is more conducive to the centering of the mover, effectively limiting the axial eccentricity of the mover and improving the durability of the shaft;

[0022] 5. The coil frame, shaft and other components are made of aluminum alloy, which effectively reduces the eddy current loss during the normal operation of the actuator;

[0023] 6. Compared with the leaf spring structure, the mechanical spring has higher reliability when the actuator works for a long time, and is low in cost and easy to replace. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a main cross-sectional view of the present invention;

[0025] Figure 2 This is a top view after removing the upper end cover;

[0026] Figure 3 The structure diagram of the movable element for matching the shaft;

[0027] Figure 4 It is a schematic diagram of the external structure of the present invention. DETAILED DESCRIPTION

[0028] The present invention is described in more detail below with reference to the accompanying drawings:

[0029] Combination Figure 1-4 The present invention provides a novel electromagnetic actuator, which includes a shaft 1, a graphite copper sleeve 2, a magnetizer 3, a permanent magnet 4, a limit nut 5, a coil frame 6, a winding coil 7, a mechanical spring 8, an upper end cover 9, a lower end cover 10, an outer cylinder 11 and an aviation plug 12; the permanent magnet 4 is bonded to the outer side of the slot of the magnetizer 3, and a slot air gap is formed between the permanent magnet 4 and the magnetizer 3 and a constant magnetic field is provided; the graphite copper sleeve 2 cooperates with the inner concave platform of the magnetizer 3 through the limit nut 5 to form a movable whole, forming a mover; the coil frame 6 is wound with enameled wire to form a winding coil 7, and is fixed to the upper end cover 9 and the lower end cover 10 by screws, so that the winding coil 7 is placed in the slot air gap of the magnetizer 3; The mechanical spring 8 is pressed between the concave platform of the magnetizer 3 and the convex platform of the end cover to provide the supporting force required for the reciprocating motion of the mover; the graphite sleeve 2 is clearance-matched with the shaft 1 to limit the freedom of movement of the mover except the axial direction, and the shaft 1 is fixed to the upper end cover 9 and the lower end cover 10 with countersunk holes at both ends by screws; the outer cylinder 11 and the upper end cover 9 and the lower end cover 10 are connected by screws to form the outer shell of the actuator; the lower end cover 10 is rigidly connected to the controlled object by bolt fixing to ensure that there is no relative displacement between the actuator and the controlled object when the actuator is working; the outlet port of the winding coil 7 is designed and installed at the bottom of the outer cylinder 11, and the external current excitation is applied through the aviation plug 12 at the wiring port.

[0030] The graphite copper sleeve 2 is assembled on the shaft 1, adhered to the magnetizer 3 and fixed by the limit nut 5 to form a mover; the permanent magnet 4 is a tile-shaped structure, and multiple permanent magnets are adhered to each other to form a ring structure, and are fixed to the outer side of the groove of the magnetizer 3 with epoxy resin; the cross-section of the magnetizer 3 is "H"-shaped, and an air gap is formed between the inner side of the groove and the permanent magnet 4; the two coil frames 6 are connected to the end covers by screws, and the upper end cover 9 and the lower end cover 10 are connected to the outer cylinder 11 by screws, and the coil frame 6 is located at the air gap structure; the winding coil 7 is wound on the coil frame 6 using enameled wire, and external excitation is applied through the aviation plug 12 at the wiring port; two mechanical springs 8 are respectively pressed between the upper end cover 9 and the lower end cover 10 and the magnetizer 3; the two end covers are rigidly connected to the two ends of the shaft 1 by screws, and are connected to the outer cylinder 11 to form the outer shell of the actuator.

[0031] The permanent magnet 4 is magnetized in a radial manner and the magnetization direction is consistent;

[0032] The permanent magnet 4 is composed of 12 identical tile-shaped structures spliced ​​into a cylindrical structure;

[0033] The outer surface of the limit nut 5 has an external thread connected to the magnetic conductor 3, and one end of the limit nut 5 close to the upper and lower end covers 9 and 10 is provided with a groove;

[0034] Two concave platforms are provided on the inner side of the magnet conductor 3, which are used to cooperate with the limit nut 5 to fix the graphite sleeve and install the spring respectively, and the concave platform near the center is provided with an internal thread;

[0035] The magnetic conductor 3 is made of electromagnetic soft iron;

[0036] The upper and lower end covers 9 and 10 are provided with a countersunk hole and a boss. The countersunk hole is located in the middle of the end cover for clamping the shaft 1 and is fixedly connected by screws. The boss is used to assemble and fix the mechanical spring 8;

[0037] The lower end cover 10 is connected to the controlled object by bolt fixing to ensure the rigid fixation of the actuator during normal operation;

[0038] The coil frame 6 is connected to the outer side of the bosses of the end covers 9 and 10 by means of screw fixing;

[0039] The shaft 1, the limit nut 5 and the coil frame 6 are made of high-strength aluminum alloy.

[0040] The present invention works based on the Lorentz force principle. Figure 1As shown, the permanent magnet 4 with radiation magnetization is arranged on the outside of the winding coil 7 to provide a constant radial magnetic field for the coil in the air gap, and the entire magnetizer 3 constructs two wide magnetic field loops above and below; alternating current is applied to the winding coil 7 through the aviation plug 12 at the wiring port, and then the coil generates an axial electromagnetic force in the air gap magnetic field. Since the winding coil 7, the upper end cover 9, and the lower end cover 10 are fixed parts, and the entire mover is an elastic constraint part, it can be seen from the interaction force that the permanent magnet 4 is also subjected to an equal and opposite electromagnetic force. The mover including the permanent magnet 4 will make corresponding axial movement under the force. When the mover moves, the mechanical spring 8 will be compressed to provide a corresponding restoring force, so that the mover can return to the initial position and make continuous reciprocating motion, and then the actuator generates an inertial force that changes with the current, which is transmitted and applied to the controlled object through the lower end cover 10 to suppress its vibration and achieve the purpose of reducing vibration and noise.

[0041] In order to reduce the axial eccentricity during the movement of the mover, the shaft 1 is clearance-matched with the graphite copper sleeve 2 and the magnet 3. At the same time, to avoid friction between the mover and other components, the gap between the coil frame 6 and the permanent magnet 4 is 0.5-1.5mm, and the gap between the coil frame 6 and the inner side of the groove of the magnet 3 is 1-2mm.

[0042] In order to make the restoring force along the axial direction, both ends of the mechanical spring 8 need to be ground so that the direction of the force does not deviate greatly during installation. In addition, springs with different numbers of turns and heights can be selected according to the mass of the mover and the volume of the actuator to adjust their stiffness.

Claims

1. A new type of electromagnetic actuator, characterized by: The invention comprises an outer cylinder, an upper end cover and a lower end cover are respectively installed at the upper and lower ends of the outer cylinder, a shaft, a magnetizer and a permanent magnet are arranged in a space formed by the upper end cover, the outer cylinder and the lower end cover, the upper and lower ends of the shaft are respectively fixedly connected with the upper end cover and the lower end cover, a magnetizer with an H-shaped cross section is installed on the outside of the shaft, a graphite copper sleeve is installed between the magnetizer and the shaft, a permanent magnet is installed in a groove with an H-shaped cross section of the magnetizer, an air gap is formed between the permanent magnet and the inner side of the groove, a coil frame is installed in the air gap, a winding coil is wound on the coil frame, mechanical springs are respectively sleeved at the upper and lower ends of the shaft, and the mechanical springs are respectively press-fitted between the upper end cover and the magnetizer and between the lower end cover and the magnetizer; the upper and lower ends of the graphite copper sleeve are on the shaft A limiting nut is sleeved, and the graphite copper sleeve is attached to the magnetizer and fixed by the limiting nut to form a mover; two recesses are provided on the inner side of the magnetizer, which are respectively used to cooperate with the limiting nut to fix the graphite sleeve and install the spring, and the recess near the center is provided with an internal thread; the outer surface of the limiting nut has an external thread connected to the magnetizer, and the limiting nut is provided with a groove at one end close to the upper end cover and the lower end cover; the upper end cover and the lower end cover are provided with countersunk holes and bosses, the countersunk holes are located in the middle of the upper end cover and the lower end cover to clamp the shaft and are fixedly connected by screws, and the bosses are assembled and fixed with mechanical springs; the coil frame is connected to the outer sides of the bosses of the upper end cover and the lower end cover by screws.

2. A novel electromagnetic actuator according to claim 1, characterized in that: The magnetic conductor is made of electromagnetic soft iron.

3. The novel electromagnetic actuator according to claim 1 is characterized in that: The gap between the coil frame and the permanent magnet is 0.5-1.5mm.

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