Permanent magnet synchronous linear motor

Abstract

The utility model discloses a permanent magnet synchronous linear motor, which comprises a base and a motor stator arranged on the base, at least one side of the motor stator is provided with a coding component along the extension direction of the motor stator, and a partition piece is arranged between the coding component and the motor stator. The partition piece is arranged close to the end portion of the permanent magnet synchronous linear motor, and the upper surface of the partition piece is higher than the upper surface of the coding assembly. According to the permanent magnet synchronous linear motor of the utility model, the end part of the permanent magnet synchronous linear motor is provided with the partition member, so that the diffusion of an end part magnetic field can be isolated or inhibited, and the position detection of the rotor magnetic plate can be optimized.

Description

Technical Field

[0001] This utility model relates to a permanent magnet synchronous linear motor, belonging to the field of motor technology. Background Technology

[0002] A permanent magnet synchronous linear motor used in logistics conveyor lines has a stator consisting of a winding iron core and a mover consisting of a permanent magnet. The motor controller needs to adjust the current output to the stator winding based on the real-time position of the mover permanent magnet, which is typically obtained precisely using a linear Hall effect sensor.

[0003] During the movement of the permanent magnet, the magnetic field at the location of a fixed linear Hall sensor changes periodically, thus detecting the position of the mover. However, the linear Hall sensor itself is a precision component and is extremely sensitive to magnetic fields. When the stator winding is energized, the end of the winding extending beyond the iron core inevitably generates a leakage magnetic field, i.e., the end effect. The end effect interferes with the magnetic field of the permanent magnet itself, causing distortion or even complete suppression of the latter. This leads to deviations in the linear Hall sensor's detection results, affecting position detection and winding current regulation, and causing the motor to become unstable or completely out of control.

[0004] The greater the distance between the linear Hall effect sensor and the motor end, the weaker the leakage magnetic field and the smaller the impact on the Hall element. Therefore, the distance between the linear Hall effect sensor and the motor end face can be increased, and it can be installed at a position where the end magnetic field decays to zero. However, increasing the distance between the linear Hall effect sensor and the motor end face also requires increasing the length of the mover permanent magnet to ensure that the latter's magnetic field can be effectively and accurately detected. This approach increases the amount of permanent magnet used, causing unnecessary material waste and increasing costs. It also increases the weight of the mover, reducing the dynamic performance of the motor.

[0005] In view of this, it is indeed necessary to improve the existing permanent magnet synchronous linear motors to solve the above problems. Utility Model Content

[0006] To solve the above-mentioned technical problems, this utility model provides a permanent magnet synchronous linear motor, which can isolate or suppress the diffusion of the end magnetic field without increasing the material cost of the mover or reducing the dynamic performance of the motor operation.

[0007] The technical solution of this utility model is:

[0008] A permanent magnet synchronous linear motor includes a base and a motor stator disposed on the base. An encoding component is provided on at least one side of the motor stator along the extension direction of the motor stator. A partition is provided between the encoding component and the motor stator. The partition is disposed near the end of the permanent magnet synchronous linear motor. The upper surface of the partition is higher than the upper surface of the encoding component.

[0009] As a further improvement of this utility model, a moving magnetic plate is provided on one side of the motor stator relative to the base, and the projection of the side of the moving magnetic plate near the encoding component on the base intersects with the projection of the encoding component on the base.

[0010] As a further improvement of this utility model, the vertical distance between the moving magnetic plate and the encoding component is between 1-3mm.

[0011] As a further improvement of this utility model, the partition is L-shaped and includes a partition portion disposed near the motor stator and a fixing portion connected to the base. The upper surface of the partition portion is lower than or flush with the upper surface of the motor stator and higher than the upper surface of the encoding component.

[0012] As a further improvement of this utility model, the encoding component includes a support member extending in the same direction as the partition and an encoding plate connected to the support member. The encoding plate extends in the same direction as the horizontal plane and is provided with a Hall element.

[0013] As a further improvement of this utility model, a gap is provided between the moving magnetic plate and the motor stator, and it can move relative to the motor stator along the extension direction of the motor stator.

[0014] As a further improvement of this utility model, the permanent magnet synchronous linear motor is provided with a line module on each of its opposite sides, and a tray is connected to the side of the moving magnetic plate opposite to the motor stator. The tray is provided with a movable component that abuts against the line module and can move relative to the line module.

[0015] As a further improvement of this utility model, the movable component is provided in two parts and respectively abuts against two line modules. The movable component includes a first movable part and a second movable part. The first movable part and the second movable part abut against the line modules respectively, and the abutting direction of the first movable part and the second movable part is perpendicular to that of the line modules.

[0016] As a further improvement of this utility model, the line module is provided with a first guide plate arranged parallel to the coding plate and a second guide plate extending in the same direction as the partition. The first movable member abuts against the first guide plate, and the second movable member abuts against the second guide plate.

[0017] As a further improvement of this utility model, the moving magnetic plate is provided in multiple forms and is arranged at intervals along the extension direction of the motor stator.

[0018] The beneficial technical effects of this utility model are as follows: The permanent magnet synchronous linear motor of this utility model sets a partition between the encoder assembly and the motor stator, and the partition is set close to the end of the permanent magnet synchronous linear motor. By setting the upper surface of the partition to be higher than the upper surface of the encoder assembly, the permanent magnet synchronous linear motor can isolate or suppress the diffusion of the end magnetic field and optimize the position detection of the mover magnetic plate without increasing the material cost of the mover or reducing the dynamic performance of the motor operation. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the combined structure of the permanent magnet synchronous linear motor and the line module according to the preferred embodiment of this utility model.

[0020] Figure 2 yes Figure 1 A schematic diagram of the combined structure of the permanent magnet synchronous linear motor and the line module from another angle.

[0021] Figure 3 yes Figure 1 A schematic diagram of the structure of a permanent magnet synchronous linear motor.

[0022] Figure 4 yes Figure 3 Enlarged view of the circle with the middle dashed line.

[0023] Figure 5 yes Figure 1 Comparison of magnetic induction intensity of permanent magnet synchronous linear motors with and without isolation components. Detailed Implementation

[0024] In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0025] Please see Figures 1 to 5 As shown, this utility model discloses a permanent magnet synchronous linear motor 100, which can isolate or suppress the diffusion of the end magnetic field without increasing the material cost of the mover or reducing the dynamic performance of the motor operation.

[0026] Specifically, the permanent magnet synchronous linear motor 100 includes a base 1 and a motor stator 2 disposed on the base 1. Along the extending direction of the motor stator 2, at least one side of the motor stator 2 is provided with an encoding component 3. A partition 4 is provided between the encoding component 3 and the motor stator 2. The partition 4 is disposed near the end of the permanent magnet synchronous linear motor 100, and the upper surface of the partition 4 is higher than the upper surface of the encoding component 3. Preferably, the partition 4 is made of a magnetically conductive material, such as cast iron or carbon steel.

[0027] A moving magnetic plate 5 is provided on one side of the motor stator 2 opposite to the base 1. Multiple moving magnetic plates 5 are provided and arranged at intervals along the extending direction of the motor stator 2. The projection of the side of the moving magnetic plate 5 closest to the encoding component 3 onto the base 1 intersects with the projection of the encoding component 3 onto the base 1. That is, the moving magnetic plate 5 is at least partially located directly above the encoding component 3, allowing the encoding component 3 to capture and sense it. Preferably, the vertical distance between the moving magnetic plate 5 and the encoding component 3 is between 1-3 mm. Optionally, the vertical distance between the moving magnetic plate 5 and the encoding component 3 is 1.8 mm, 2 mm, or 2.2 mm.

[0028] A gap is provided between the moving magnetic plate 5 and the motor stator 2, and the moving magnetic plate 5 can move relative to the motor stator 2 along the extension direction of the motor stator 2. That is, the movement of the moving magnetic plate 5 generates a change in the magnetic field, which is captured and sensed by the encoding component 3, and then the position of the moving magnetic plate 5 is determined.

[0029] In this embodiment, the partition 4 is L-shaped and includes a partition portion 41 located near the motor stator 2 and a fixing portion 42 connected to the base 1. The upper surface of the partition portion 41 is lower than or flush with the upper surface of the motor stator 2 and higher than the upper surface of the encoding assembly 3. Generally, the partition effect of the partition portion 41 can be achieved when the upper surface of the partition portion 41 is higher than the upper surface of the encoding assembly 3. Setting the upper surface of the partition portion 41 to be lower than or flush with the upper surface of the motor stator 2 can further enhance the partition effect of the partition portion 41. Preferably, the partition portion 41 is flush with the motor stator 2. Specifically, the encoding assembly 3 includes a support member 31 extending in the same direction as the partition portion 41 and an encoding plate 32 connected to the support member 31. The encoding plate 32 extends in the same direction as the horizontal plane and is provided with a Hall element (not shown). The Hall element is a linear Hall element, which detects the position of the moving magnetic plate 5 located above by sensing the periodic changes in the magnetic field.

[0030] For details, please refer to [link / reference]. Figure 5The experimental data of Hall detection magnetic field comparison shown shows that when the motor is powered on, the moving magnetic plate travels a distance of a pair of magnetic poles in one electric cycle. The magnetic induction intensity is compared with and without the partition 4. It can be seen that when the partition 4 is present (at this time, the upper surface of the partition 41 is higher than the upper surface of the encoding component 3), the change curve of magnetic induction intensity is similar to that when it is not powered on, and is close to an ideal sine wave. In contrast, when the partition 4 is not present, the magnetic induction intensity is significantly suppressed and distorted.

[0031] The permanent magnet synchronous linear motor 100 has a line module 6 on each of its opposite sides. The moving magnetic plate 5 is connected to a tray 7 on the side opposite to the motor stator 2. The tray 7 has a movable component 71 that abuts against the line module 6 and is movable relative to the line module 6. The movable component 71 is preferably a pulley, and the pulley can be a caster wheel.

[0032] The movable component 71 has two parts and abuts against two line modules 6 respectively. The movable component 71 includes a first movable part 711 and a second movable part 712. The first movable part 711 and the second movable part 712 abut against the line module 6 respectively, and the abutting direction of the first movable part 711 and the second movable part 712 is perpendicular to that of the line module 6.

[0033] The line module 6 is provided with a first guide plate 61 arranged parallel to the encoding plate 32 and a second guide plate 62 extending in the same direction as the partition part 41. The first movable member 711 abuts against the first guide plate 61, and the second movable member 712 abuts against the second guide plate 62.

[0034] In other words, the first guide plate 61 is horizontally arranged to allow the first movable member 711 to move horizontally, that is, to move in the extension direction of the motor stator 2. The second guide plate 62 is vertically arranged and located on the side of the corresponding movable member opposite to the permanent magnet synchronous linear motor 100. The two second guide plates 62 clamp the tray 7 and the permanent magnet synchronous linear motor 100 in the middle. Therefore, the two second guide plates 62 serve a limiting function, that is, restricting the tray from moving in a fixed direction.

[0035] In summary, the permanent magnet synchronous linear motor 100 of this utility model provides a partition 4 between the encoder assembly 3 and the motor stator 2, with the partition 4 positioned close to the end of the permanent magnet synchronous linear motor 100. By setting the upper surface of the partition 4 to be higher than the upper surface of the encoder assembly 3, the permanent magnet synchronous linear motor 100 can isolate or suppress the diffusion of the end magnetic field and optimize the position detection of the mover magnetic plate without increasing the material cost of the mover or reducing the dynamic performance of the motor operation.

[0036] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A permanent magnet synchronous linear motor, characterized in that, The device includes a base and a motor stator disposed on the base. Along the extension direction of the motor stator, at least one side of the motor stator is provided with an encoding component. A partition is provided between the encoding component and the motor stator. The partition is disposed near the end of the permanent magnet synchronous linear motor, and the upper surface of the partition is higher than the upper surface of the encoding component.

2. The permanent magnet synchronous linear motor according to claim 1, characterized in that, The motor stator has a moving magnetic plate on one side relative to the base, and the projection of the side of the moving magnetic plate near the encoding component on the base intersects with the projection of the encoding component on the base.

3. The permanent magnet synchronous linear motor according to claim 2, characterized in that, The vertical distance between the moving magnetic plate and the encoding component is between 1 and 3 mm.

4. The permanent magnet synchronous linear motor according to claim 2, characterized in that, The partition is L-shaped and includes a partition portion located near the motor stator and a fixing portion connected to the base. The upper surface of the partition portion is lower than or flush with the upper surface of the motor stator and higher than the upper surface of the encoding assembly.

5. The permanent magnet synchronous linear motor according to claim 4, characterized in that, The encoding assembly includes a support member extending in the same direction as the partition and an encoding plate connected to the support member. The encoding plate extends in the same direction as the horizontal plane and is provided with a Hall element.

6. The permanent magnet synchronous linear motor according to claim 5, characterized in that, The moving magnetic plate is provided with a gap between itself and the motor stator, and can move relative to the motor stator along the extension direction of the motor stator.

7. The permanent magnet synchronous linear motor according to claim 6, characterized in that, The permanent magnet synchronous linear motor is provided with a line module on each of its opposite sides. The side of the moving magnetic plate opposite to the motor stator is connected to a tray. The tray is provided with a movable component that abuts against the line module and can move relative to the line module.

8. The permanent magnet synchronous linear motor according to claim 7, characterized in that, The movable component has two parts, which respectively abut against two line modules. The movable component includes a first movable part and a second movable part. The first movable part and the second movable part abut against the line modules respectively, and the abutting direction of the first movable part and the second movable part is perpendicular to that of the line modules.

9. The permanent magnet synchronous linear motor according to claim 8, characterized in that, The line module is provided with a first guide plate arranged parallel to the encoding plate and a second guide plate extending in the same direction as the partition. The first movable member abuts against the first guide plate, and the second movable member abuts against the second guide plate.

10. The permanent magnet synchronous linear motor according to claim 2, characterized in that, The moving magnetic plate is provided in multiple portions and is arranged at intervals along the extension direction of the motor stator.

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