Stator structure and electromagnetic brake for ultra-low temperature

Abstract

The utility model relates to the technical field of brake, provide a kind of stator structure and super low temperature electromagnetic brake, stator structure includes magnetic yoke and is located in the unlocking coil and heating coil of magnetic yoke, heating coil includes two wires, two wires are bonded together as a wire winding, and the current direction in two wires is opposite.The utility model designs the structure of double wire and winding and current reverse for heating coil, when current passes, the magnetic field size generated by two wires is equal, direction is opposite, mutually offsets, so that heating coil realizes resistance heating function while, its external magnetic field is almost zero.This fundamentally eliminates the interference problem of heating coil operating magnetic field to unlocking coil magnetic field in prior art, guarantees the independence and stability of unlocking coil magnetic field distribution, so as to ensure that electromagnetic brake unlocking response is rapid, attraction force is accurate and reliable.

Description

Technical Field

[0001] This utility model relates to the field of brake technology, and more specifically, to a stator structure and an electromagnetic brake for cryogenic applications. Background Technology

[0002] As a key actuator in mechanical transmission systems, brakes are widely used in drive devices in many fields such as aerospace, polar exploration, and cryogenic experimental equipment. In some special applications, brakes need to operate in cryogenic environments of -150°C or even lower for extended periods.

[0003] Currently, for power-off electromagnetic brakes, in order to solve the problem of brakes failing to work properly due to icing in ultra-low temperature environments, two sets of independently controllable coils are usually set in the stator. One set of coils serves as the unlocking coil, which attracts the armature when energized to release the brake; the other set of coils serves as the heating coil, which keeps energized to heat and achieve the purpose of breaking ice.

[0004] However, the heating coil generates a magnetic field when it is working in the above method. This magnetic field can easily interfere with the magnetic field generated when the unlocking coil is working, disrupting the magnetic field distribution pattern of the unlocking coil and affecting the stability and accuracy of the electromagnetic force output. At best, it will cause the brake unlocking action to be delayed and the attraction force to be insufficient; at worst, it will directly cause the unlocking failure. Utility Model Content

[0005] The purpose of this invention is to provide a stator structure and an electromagnetic brake for cryogenic use, so as to solve the above-mentioned defects of the prior art.

[0006] This utility model is achieved through the following technical solution: A stator structure includes a magnetic yoke and an unlocking coil and a heating coil disposed in the magnetic yoke. The heating coil includes two wires that are wound together as a single wire, and the current in the two wires is in opposite directions.

[0007] Furthermore, one end of the magnetic yoke is provided with two annular grooves along the radial direction, and the unlocking coil and the heating coil are each disposed in one of the annular grooves.

[0008] Furthermore, the inner wall of the annular groove where the heating coil is located is coated with a coating capable of absorbing electromagnetic energy.

[0009] Furthermore, the coating material is carbonyl iron.

[0010] This utility model also provides an electromagnetic brake for cryogenic applications, comprising an armature, a rotor, a flange, and a stator structure as described in any one of the above. The flange, rotor, armature, and magnetic yoke are arranged in sequence, and the flange is fixedly connected to the magnetic yoke.

[0011] Furthermore, the magnetic yoke is connected to the flange by connecting screws, and a positioning sleeve is fitted on the connecting screws to limit the distance between the magnetic yoke and the flange.

[0012] Furthermore, the positioning sleeve is a bolt with a through hole in the center and is connected to the magnetic yoke by a thread.

[0013] Furthermore, friction plates are provided on both sides of the rotor.

[0014] Furthermore, a dust cover is provided between the flange and the magnetic yoke to seal the gap between them.

[0015] The technical solution of this utility model has at least the following advantages and beneficial effects: In this utility model, the heating coil is designed as a double-wire winding structure with opposite currents. When current passes through, the magnetic fields generated by the two wires are equal in magnitude and opposite in direction, canceling each other out. This makes the heating coil achieve resistance heating while its external magnetic field is almost zero. This fundamentally eliminates the problem of interference between the working magnetic field of the heating coil and the magnetic field of the unlocking coil in the prior art, ensuring the independence and stability of the magnetic field distribution of the unlocking coil, thereby ensuring that the electromagnetic brake has a rapid unlocking response and a precise and reliable attraction force. Attached Figure Description

[0016] Figure 1 A front view of an electromagnetic brake for cryogenic applications provided by this utility model; Figure 2 for Figure 1 AA section view in the middle; Reference numerals: 1-Magnetic yoke, 2-Armature, 3-Rotor, 4-Flange, 5-Unlocking coil, 6-Heating coil, 7-Connecting screw, 8-Positioning sleeve, 9-Mounting bolt, 10-Dust cover. Detailed Implementation

[0017] refer to Figure 1 and Figure 2 A stator structure includes a magnetic yoke 1, an unlocking coil 5, and a heating coil 6 disposed within the yoke 1. The heating coil 6 comprises two wires wound together as a single conductor, with the currents in the two wires flowing in opposite directions. Essentially, the two wires are tightly joined together and wound as a single conductor. Furthermore, in practical applications, the currents in the two wires of the heating coil 6 always flow in opposite directions. When current passes through, the magnetic fields generated by the two wires are equal in magnitude and opposite in direction, canceling each other out. This ensures that while the heating coil 6 achieves resistive heating, its external magnetic field is nearly zero. This fundamentally eliminates the interference problem of the working magnetic field of the heating coil 6 on the magnetic field of the unlocking coil 5 in existing technologies, ensuring the independence and stability of the magnetic field distribution of the unlocking coil 5, thereby ensuring rapid unlocking response and precise and reliable engagement force of the electromagnetic brake.

[0018] The magnetic yoke 1 has two radially arranged annular grooves at one end. The unlocking coil 5 and the heating coil 6 are each disposed in one of the annular grooves, meaning that the unlocking coil 5 and the heating coil 6 are independently disposed in two annular grooves. For example, in this embodiment, the heating coil 6 is disposed in the outer annular groove and the unlocking coil 5 is disposed in the inner annular groove. In other embodiments, the heating coil 6 can also be disposed in the inner annular groove and the unlocking coil 5 in the outer annular groove; at the same time, it should be understood that in some embodiments, the unlocking coil 5 and the heating coil 6 can also be disposed in the same annular groove.

[0019] Based on the above, in this embodiment, the inner wall of the annular groove containing the heating coil 6 is coated with a coating capable of absorbing electromagnetic energy. It is worth noting that although designing the heating coil 6 with a double-wire parallel winding and reversed current structure can make the external magnetic field almost zero, considering the slight alternating magnetic field that may be generated by high-frequency harmonics or instantaneous unbalanced currents, spraying an electromagnetic energy absorbing coating on the inner wall of the annular groove containing the heating coil 6 can further attenuate and absorb this residual electromagnetic energy. This is equivalent to providing "double insurance" for suppressing interference, maximizing the purification of the working magnetic environment of the unlocking coil 5, and improving the anti-interference capability and stability of the entire system under complex electromagnetic conditions. Simultaneously, the electromagnetic energy absorbed by the coating is radiated as heat energy, further improving the heating effect. As an option, carbonyl iron is chosen as the coating material in this embodiment; in other embodiments, other materials capable of absorbing electromagnetic energy can of course be chosen for the coating material, such as iron-silicon-aluminum, iron-based amorphous materials, iron-nickel-based nanocrystals, etc.

[0020] This embodiment also provides an electromagnetic brake for cryogenic applications, including an armature 2, a rotor 3, a flange 4, and the aforementioned stator structure. The flange 4, rotor 3, armature 2, and magnetic yoke 1 are arranged sequentially, with the flange 4 fixedly connected to the magnetic yoke 1. It should be understood that in practical applications, a spring (not shown) should also be included. The spring is positioned between the magnetic yoke 1 and the armature 2. Specifically, a blind hole (not shown) can be provided on the side of the magnetic yoke 1 near the armature 2, and the spring is installed within the blind hole. Those skilled in the art should understand that the working principle of the above brake is as follows: The heating coil 6 mainly functions as a heating element and can be independently switched on and off as needed, for example, always kept energized to maintain the brake at a constant temperature (e.g., 20°C). When the unlocking coil 5 is de-energized, the armature 2 presses the rotor 3 under the action of the spring, thereby achieving braking; when the unlocking coil 5 is energized, the magnetic yoke 1 attracts the armature 2, releasing the pressure on the rotor 3, thereby releasing the brake.

[0021] In this embodiment, friction plates are provided on both sides of the rotor 3, which facilitates the increase of friction by selecting friction materials with a higher coefficient of friction, thereby increasing the braking torque. The method of fixing the friction plates is not limited, but adhesive fixing is preferred.

[0022] In this embodiment, the magnetic yoke 1 and flange 4 are fixedly connected as follows: the magnetic yoke 1 and flange 4 are connected by connecting screws 7, and a positioning sleeve 8 is fitted on the connecting screws 7. One end of the positioning sleeve 8 abuts against the magnetic yoke 1, and the other end abuts against the flange 4, thereby limiting the distance between the magnetic yoke 1 and flange 4. It is easy to understand that, based on this, the armature 2 is provided with a guide opening for the positioning sleeve 8 to pass through, facilitating the radial positioning of the armature 2, and simultaneously using the positioning as a guide for the movement of the armature 2. The form of the guide opening is not limited; for example, it can be a through hole or a notch set on the outer edge of the armature 2. Furthermore, in practical applications, mounting holes can be provided on the flange 4, and mounting bolts 9 can be installed in the mounting holes to fix the entire brake to the mounting surface using the mounting bolts 9.

[0023] Furthermore, in this embodiment, the positioning sleeve 8 is a bolt with a central through hole, and the bolt is connected to the magnetic yoke 1 by threads. It is worth noting that with this configuration, the distance between the magnetic yoke 1 and the flange 4 can be adjusted by changing the depth to which the positioning sleeve 8 is screwed into the magnetic yoke 1. After the friction plate wears, the brake can be kept in normal operation by reducing the distance between the magnetic yoke 1 and the flange 4.

[0024] In this embodiment, a dust cover 10 is provided between the flange 4 and the magnetic yoke 1 to seal the gap between them and provide dust protection. Alternatively, the dust cover 10 can be installed as follows: both ends of the dust cover 10 have annular locking blocks, and the outer sides of the flange 4 and the magnetic yoke 1 have annular grooves that mate with the locking blocks. It is easy to understand that the dust cover 10 is typically made of plastic and has a certain degree of elasticity; during installation, the annular locking blocks of the dust cover 10 are simply inserted into the annular grooves. In other embodiments, the dust cover 10 can also be installed in other ways, such as by connecting and fastening it to the flange 4 and the magnetic yoke 1 with screws respectively.

[0025] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A stator structure, comprising a magnetic yoke and an unlocking coil and a heating coil disposed in the magnetic yoke, characterized in that, The heating coil consists of two wires that are joined together as a single wire and wound around each other, with the current flowing in opposite directions in the two wires.

2. The stator structure according to claim 1, characterized in that, The magnetic yoke has two annular grooves along the radial direction at one end, and the unlocking coil and the heating coil are each located in one of the annular grooves.

3. The stator structure according to claim 2, characterized in that, The inner wall of the annular groove where the heating coil is located is coated with a coating capable of absorbing electromagnetic energy.

4. The stator structure according to claim 3, characterized in that, The coating material is carbonyl iron.

5. An electromagnetic brake for cryogenic applications, characterized in that, It includes an armature, a rotor, a flange, and a stator structure as described in any one of claims 1-4, wherein the flange, rotor, armature, and magnetic yoke are arranged in sequence, and the flange is fixedly connected to the magnetic yoke.

6. The electromagnetic brake for cryogenic applications according to claim 5, characterized in that, The magnetic yoke is connected to the flange by connecting screws, and a positioning sleeve is fitted on the connecting screws to limit the distance between the magnetic yoke and the flange.

7. The electromagnetic brake for cryogenic applications according to claim 6, characterized in that, The positioning sleeve is a bolt with a through hole in the center and is connected to the magnetic yoke by threads.

8. The electromagnetic brake for cryogenic applications according to claim 5, characterized in that, Friction plates are provided on both sides of the rotor.

9. The electromagnetic brake for cryogenic applications according to claim 5, characterized in that, A dust cover is provided between the flange and the magnetic yoke to seal the gap between them.

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