Variable stroke cylindrical linear motor drive

Abstract

The application belongs to the technical field of electric machines, and discloses a variable-stroke cylindrical linear motor driving device, which comprises a primary assembly, a secondary assembly and an I-shaped guide rail support, the primary assembly comprises at least one cylindrical primary, a through groove which is communicated with the inner cavity of the cylindrical primary is formed on the side wall of the cylindrical primary along the direction of the central axis, there is a groove between the guide rails of the I-shaped guide rail support, the cylindrical primary is fixed in the groove, the through groove faces upward, the central axis of the cylindrical primary is parallel to the direction of the guide rails, the cylindrical primary is connected with an external control system, the secondary assembly comprises a ferromagnetic cylindrical core and a cavity-outside projectile, the cavity-outside projectile is arranged above the cylindrical primary and is connected with the guide rails and can slide in cooperation with the guide rails, a connecting piece is arranged in the through groove, the upper end and the lower end of the connecting piece are connected with the ferromagnetic cylindrical core and the cavity-outside projectile respectively, and the ferromagnetic cylindrical core is suspended in the inner part of the cylindrical primary. The device can avoid the electromagnetic thrust fluctuation caused by the end magnetic field distortion.

Description

Technical Field

[0001] This invention belongs to the field of motor technology, and more specifically, relates to a variable stroke cylindrical linear motor drive device. Background Technology

[0002] Currently, most linear motors on the market are permanent magnet linear motors, including cylindrical linear motors. However, permanent magnet linear motors suffer from "end-field effect" due to the distortion of the magnetic field at their ends. This affects the integrity of the internal traveling wave magnetic field, increasing motor losses and reducing thrust, resulting in some fluctuations during linear motor operation. Secondly, linear motors are difficult to control because load changes, system parameter perturbations, various disturbances, and end-field effects all directly affect the motor during operation without any buffering or mitigation mechanisms, leading to system instability and performance degradation. The stroke of a conventional cylindrical linear motor is usually relatively short, and its length is limited because its mover is generally supported by linear bearings or sliding bushings. The outer ring of the linear bearing or sliding bushing is fixed to the end cover of the linear motor, and its inner ring is a cylinder with a stroke length roughly the same as the motor's stroke length. This cylinder is fixed to the shafts at both ends of the mover. When the motor stroke is long, the length of the mover shaft also increases accordingly. However, the stiffness of the shaft decreases after the increase. At the same time, the magnetic pull of the permanent magnet in the permanent magnet motor can cause the shaft to bend. Therefore, the uniformity of the air gap of the motor cannot be guaranteed. Especially when the outer diameter of the motor is small, it can cause the motor to fail to operate normally.

[0003] Current linear motors can be launched in both forward and backward directions via a control box. However, the thrust of the linear motor can only be indirectly increased by adjusting the supply current, and it only allows for launching to the end in one direction. It cannot start or stop the linear motor at any point within its stroke. Therefore, research on novel ultra-high-speed, high-thrust, long-stroke linear motors is of great significance. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a variable stroke cylindrical linear motor drive device, which mainly solves the problem that the existing linear motor is prone to system instability and performance degradation after the stroke is increased.

[0005] To achieve the above objectives, the present invention provides a variable stroke cylindrical linear motor drive device, comprising a primary assembly, a secondary assembly, and an I-shaped guide rail bracket, wherein:

[0006] The primary component includes at least one cylindrical primary, and a through groove is formed on the side wall of the cylindrical primary along the central axis, so that the end face of the cylindrical primary is an open circle.

[0007] The I-shaped guide rail bracket is symmetrically provided with guide rails, and grooves are formed between the guide rails. The cylindrical primary is fixed in the grooves, and the through grooves face upwards. The central axis of the cylindrical primary is parallel to the direction of the guide rails.

[0008] The secondary component includes a ferromagnetic cylindrical iron core and an external emitter. The external emitter is disposed above the through slot and connected to the guide rail. A connector is provided through the through slot. The lower end of the connector is connected to the ferromagnetic cylindrical iron core, and the upper end of the connector is connected to the external emitter, so that the ferromagnetic cylindrical iron core is suspended inside the cylindrical primary component.

[0009] The cylindrical primary can be connected to an external control system. When the external control system powers the cylindrical primary, the cylindrical primary generates a positive magnetic field and a reverse magnetic field. Under the action of the positive and reverse magnetic fields, the ferromagnetic cylindrical iron core can drive the external emitter to move from any end of the cylindrical primary to the other end along the central axis of the cylindrical primary.

[0010] Furthermore, when there are at least two cylindrical primary sections, adjacent cylindrical primary sections are coaxially arranged and connected to each other, and the through slots are aligned sequentially. After being energized, the ferromagnetic cylindrical core can accelerate from the previous cylindrical primary section to the next cylindrical primary section. Preferably, the connected cylindrical primary sections abut or separate from each other.

[0011] Furthermore, the cylindrical primary includes a cylindrical permanent magnet and a coil winding. The cylindrical permanent magnet has a through slot on its side parallel to its central axis. The coil winding is wound around the cylindrical permanent magnet in the circumferential direction until it completely covers the cylindrical permanent magnet, forming a cylindrical primary with the through slot.

[0012] Furthermore, the coil winding is a single-layer coil winding or a multi-layer coil winding composed of multiple tightly bonded coils; preferably, when there are two or more cylindrical primary windings, the number of turns of the coil windings of adjacent cylindrical primary windings is the same or different; more preferably, when there are two or more cylindrical primary windings, the number of winding layers of the coil windings of adjacent cylindrical primary windings is the same or different.

[0013] Furthermore, the cylindrical permanent magnet is made of an interference medium with high magnetic permeability and low electrical conductivity to prevent eddy current heating.

[0014] Furthermore, the two ends of the connector are respectively welded to the external emitter and the ferromagnetic cylindrical iron core. When the ferromagnetic cylindrical iron core moves, the connector does not contact the side wall of the through groove.

[0015] Furthermore, the linear motor drive device also includes a position sensor, which is used to detect the movement position of the secondary component and transmit the movement position information to the external control system; preferably, the linear motor drive device also includes a grating sensor, which is used to detect the movement distance of the secondary component and transmit the movement distance to the external control system.

[0016] Furthermore, the external control system is individually connected to each cylindrical primary, and the external control system is used to provide each cylindrical primary with a current of the same or different magnitude.

[0017] Furthermore, a connecting structure is provided on the end faces of both ends of the cylindrical primary. When the primary component includes multiple cylindrical primarys, adjacent cylindrical primarys are connected by the connecting structures arranged opposite to each other.

[0018] Furthermore, an insulating support frame is provided between the cylindrical primary and the groove. The thickness of the insulating support frame in the middle is greater than the thickness of its two ends. The cylindrical primary is fixed in the middle position of the insulating support frame, and the two ends of the insulating support frame are fixed on the groove.

[0019] Compared with the prior art, the above technical solutions conceived by this invention have the following main advantages:

[0020] 1. The primary component of this invention includes at least one, and there is no upper limit to the number of primary components. The more primary components there are, the longer the motor travel stroke. The ferromagnetic cylindrical iron core of the secondary component is connected to the external moving body through a connector. The external moving body and the guide rail can slide together, so that the ferromagnetic cylindrical iron core is suspended inside the cylindrical primary to achieve rigid fixation (i.e., it does not contact the inner wall of the cylindrical primary). Therefore, compared with the solution of extending the travel stroke by increasing the secondary in the existing linear motor, the linear motor of this invention will not cause the problem of stiffness instability of the linear motor device after extending the travel stroke. In addition, the cylindrical primary can generate a positive magnetic field and a reverse magnetic field after being energized. The direction and intensity of the magnetic field can change with the direction and magnitude of the current. Under the action of the positive magnetic field and the reverse magnetic field, the ferromagnetic cylindrical iron core can move along the through slot from any end of the cylindrical primary to the other end of the cylindrical primary, without being restricted by a single direction.

[0021] 2. In this invention, when there are two or more cylindrical primary stages, adjacent cylindrical primary stages are coaxially connected and their through slots are aligned sequentially, so that the ferromagnetic cylindrical iron core can accelerate unimpededly from the previous cylindrical primary stage to the next cylindrical primary stage. By accelerating step by step in each cylindrical primary stage, an electromagnetic catapult effect with ultra-high speed and ultra-long stroke is achieved.

[0022] 3. The cylindrical primary of the present invention includes a cylindrical permanent magnet and a coil winding wound on the cylindrical permanent magnet. The cylindrical permanent magnet is made of an interference medium with high magnetic permeability and low electrical conductivity, which can avoid eddy current heating. A through slot parallel to its central axis is opened on the side of the cylindrical permanent magnet. The coil winding is wound around the circumferential direction of the cylindrical permanent magnet until it completely covers the cylindrical permanent magnet, thereby forming a cylindrical primary with a through slot. The connector passes through the through slot. When the ferromagnetic cylindrical iron core drives the external cavity emitter to move at high speed, the connector does not contact the side wall of the through slot, thus avoiding affecting the movement speed.

[0023] 4. When the external control system of the linear motor drive device of the present invention inputs current and control signals, since the external control system is connected to each cylindrical primary individually, each cylindrical primary can produce magnetic fields with different or the same direction covering the entire track, thereby generating electromagnetic thrust in the secondary, enabling the ferromagnetic cylindrical iron core to accelerate step by step, move continuously, or change direction. Compared with permanent magnet linear motors, this simplifies the control difficulty and the corresponding primary coil winding difficulty. Furthermore, since the magnetic field can cover the entire motion track, it avoids the magnetic field distortion at the end of the permanent magnet linear motor from affecting the internal magnetic field and causing fluctuations in the electromagnetic thrust. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the variable stroke cylindrical linear motor drive device provided in an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the secondary component structure provided in the embodiments of the present invention;

[0026] Figure 3 This is a cross-sectional view of the positional structure of a single cylindrical primary and a ferromagnetic cylindrical iron core provided in an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the magnetic field and thrust formation of the cylindrical linear motor drive device in an embodiment of the present invention.

[0028] Figure 5 This is a schematic diagram of the primary component structure provided in an embodiment of the present invention;

[0029] Figure 6 This is a schematic diagram of the fixing of the ferromagnetic cylindrical iron core and the primary bottom support provided in an embodiment of the present invention;

[0030] Figure 7 This is a schematic diagram of the primary bottom support provided in an embodiment of the present invention.

[0031] In the diagram: 1-I-shaped guide rail bracket, 11-guide rail, 12-groove, 13-grating sensor, 14-position sensor, 2-cylindrical primary, 21-through slot, 22-coil winding, 23-interference medium, 24-end face connection hole, 25-side wall connection hole, 26-primary bottom bracket, 261-fixing hole, 262-middle connection hole, 3-ferromagnetic cylindrical iron core, 31-mounting groove, 32-external emitter, 33-connector, 4-external control system. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0033] This invention provides a variable stroke cylindrical linear motor drive device, which includes a primary component, a secondary component, and an I-shaped guide rail bracket, wherein:

[0034] The primary component includes at least one cylindrical primary, and a through groove communicating with the inner cavity of the cylindrical primary is provided on the side wall along the central axis direction, so that the end face of the cylindrical primary is an open circle.

[0035] The I-shaped guide rail bracket is symmetrically equipped with guide rails, and grooves are formed between the guide rails. The cylindrical primary is fixed in the grooves, and the through grooves face upwards. The central axis of the cylindrical primary is parallel to the direction of the guide rails. The cylindrical primary is connected to an external control system, which is a conventional motor control system such as a linear motor controller.

[0036] The secondary assembly includes a ferromagnetic cylindrical iron core and an external emitter. The length of the ferromagnetic cylindrical iron core is fixed and is generally shorter than that of the primary assembly. The external emitter is positioned above the cylindrical primary and connected to a guide rail, allowing it to slide in conjunction with the guide rail. A connector passes through the slot, with its lower end connected to the ferromagnetic cylindrical iron core and its upper end connected to the external emitter, causing the ferromagnetic cylindrical iron core to suspend inside the cylindrical primary. When the cylindrical primary is energized, it generates a positive magnetic field and a reverse magnetic field. Under the influence of these two magnetic fields, the ferromagnetic cylindrical iron core can move the external emitter from one end of the cylindrical primary to the other end along the central axis of the cylindrical primary. Specifically, under the influence of the positive magnetic field, after the ferromagnetic cylindrical iron core moves from one end of the cylindrical primary to the middle, it changes the direction of the current to change the direction of the magnetic field, generating a reverse magnetic field inside the cylindrical primary. Under the thrust of the reverse magnetic field, the ferromagnetic cylindrical iron core continues to move from the middle of the cylindrical primary to the other end.

[0037] In a preferred embodiment, when there are two or more cylindrical primary components, adjacent cylindrical primary components are coaxially arranged and connected to each other, and the through slots are aligned sequentially. After being energized, the ferromagnetic cylindrical core can accelerate from the previous cylindrical primary component to the next cylindrical primary component. Preferably, the connected cylindrical primary components abut or separate. Even if they separate, it will hardly affect the accelerated movement of the moving part (i.e., the ferromagnetic cylindrical core) inside the cylindrical primary component.

[0038] In a preferred embodiment, the cylindrical primary includes a cylindrical permanent magnet and a coil winding. The cylindrical permanent magnet has a through slot on its side parallel to its central axis, so its end face is also C-shaped (i.e., an open circle). The coil winding is wound around the cylindrical permanent magnet in the circumferential direction until it completely covers the cylindrical permanent magnet, forming a cylindrical primary with a through slot.

[0039] In a more preferred embodiment, the coil winding is a single-layer coil winding or a multi-layer coil winding composed of multiple tightly bonded coils. The more layers there are, the greater the current required in practical applications. Preferably, when there are two or more cylindrical primary windings, the number of turns of the coil windings of adjacent cylindrical primary windings is the same or different. When the number of turns is different, the thrust generated by the magnetic field in the current cylindrical primary will be different. More preferably, when there are two or more cylindrical primary windings, the number of winding layers of the coil windings of adjacent cylindrical primary windings is the same or different.

[0040] In a more preferred embodiment, the cylindrical permanent magnet is made of an interference medium with high magnetic permeability and low electrical conductivity to prevent eddy current heating.

[0041] In a preferred embodiment, the two ends of the connector are welded to the external emitter and the ferromagnetic cylindrical iron core, respectively, to achieve rigid fixation of the ferromagnetic cylindrical iron core, and the connector does not contact the side wall of the through groove when the ferromagnetic cylindrical iron core moves.

[0042] In a preferred embodiment, the linear motor drive device further includes a position sensor for detecting the movement position of the secondary component, which may be disposed in the groove.

[0043] In a preferred embodiment, the linear motor drive device further includes a grating sensor, which is used to detect the movement distance of the secondary component. The grating sensor can be set on the groove. The external control system is used to receive the information detected by the position sensor and the grating sensor, and control the movement speed and position of the ferromagnetic cylindrical iron core based on the information, so that the ferromagnetic cylindrical iron core can be started and stopped at will during the movement.

[0044] In a preferred embodiment, an external control system is individually connected to each cylindrical primary, and the external control system is used to provide each cylindrical primary with a current of the same or different magnitude.

[0045] In a preferred embodiment, a connecting structure is provided on the end faces of both ends of the cylindrical primary. When the primary component includes multiple cylindrical primarys, adjacent cylindrical primarys are connected by the connecting structures arranged opposite to each other.

[0046] In a preferred embodiment, an insulating support frame is also provided between the cylindrical primary and the groove. The thickness of the insulating support frame in the middle is greater than the thickness of its two ends. The cylindrical primary is fixed in the middle position of the insulating support frame, and the two ends of the insulating support frame are fixed on the groove, so as to leave enough space for other structural components such as position sensors or grating sensors and avoid mutual interference.

[0047] To illustrate the present invention, the aforementioned method provided by the present invention will be described in detail below with reference to embodiments. However, the following embodiments should not be construed as limiting the scope of protection of the present invention.

[0048] Example 1

[0049] Figure 1 This embodiment provides a schematic diagram of a variable stroke cylindrical linear motor drive device. The device includes a primary component, a secondary component, and an I-shaped guide rail bracket 1, and its specific structure is as follows:

[0050] The primary component includes five cylindrical primary components 2, which are coaxially arranged and connected end to end. Each cylindrical primary component 2 has a through groove 21 on its side wall along the central axis direction, which communicates with the inner cavity of the cylindrical primary component 2, so that the end face of the cylindrical primary component 2 is an open circle.

[0051] Two guide rails 11 are mounted on an I-shaped guide rail bracket 1. There is a groove 12 between the two guide rails 11. The cylindrical primary 2 is fixed in the groove 12, and its through groove 21 is set upward. The central axis of the cylindrical primary 2 is parallel to the direction of the guide rails 11. The cylindrical primary 2 is connected to an external control system 4. The external control system 4 is a conventional electronic control system, such as a linear motor controller, a direct drive motor controller, or a linear control driver. It should be known that those skilled in the art are familiar with the structural features of conventional electronic control systems, so they are not the focus of this invention.

[0052] like Figure 2 As shown, the secondary assembly includes a ferromagnetic cylindrical iron core 3 and an external emitter 32, such as... Figure 3 As shown, the length of the ferromagnetic cylindrical iron core 3 is generally shorter than the length of the cylindrical primary 2; the external emitter 32 is positioned above the cylindrical primary 2 and connected to the guide rail 11, allowing it to slide in conjunction with the guide rail 11; a sheet-like connector 33 passes through the through slot 21, with its upper end welded to the external emitter 32 and its lower end welded to the ferromagnetic cylindrical iron core 3, thus enabling the ferromagnetic cylindrical iron core 3 to suspend inside the cylindrical primary 2; the cylindrical primary 2 generates a positive magnetic field and a reverse magnetic field after being energized, such as... Figure 4As shown, when the external control system 4 supplies an electrical signal to the cylindrical primary 2, the cylindrical primary 2 generates a full-coverage magnetic field from the N pole to the S pole in the direction of the arrow. The ferromagnetic cylindrical iron core 3 also has N and S poles. Under the physical characteristics of the magnetic field, the ferromagnetic cylindrical iron core 3 will be subjected to a positive magnetic field thrust F and begin to accelerate until it reaches the middle of the cylindrical primary 2. At this point, the ferromagnetic cylindrical iron core 3 is at the center of the magnetic field, where there is no thrust. If no adjustment or control is applied at this point, the ferromagnetic cylindrical iron core 3 will continue to move forward under the action of inertia. However, when the ferromagnetic cylindrical iron core 3 approaches the other end of the cylindrical primary 2, it will be subjected to the force of the cylindrical primary 2. The repulsive force applied at the other end of primary 2 causes the ferromagnetic cylindrical core 3 to move in the opposite direction, returning to the middle of the cylindrical primary 2 (i.e., the center of the magnetic field). Therefore, when the ferromagnetic cylindrical core 3 moves from one end of the cylindrical primary 2 to the middle (i.e., from one end of the magnetic field to the center of the magnetic field), it is necessary to change the direction of the magnetic field (i.e., change the direction of the current supplied to the cylindrical primary 2 by the external control system 4). This allows the ferromagnetic cylindrical core 3 to continue moving forward under the action of inertia while being pulled by the other end of the cylindrical primary, thus keeping the direction of motion of the ferromagnetic cylindrical core 3 unchanged and continuing to accelerate until it reaches the other end of the cylindrical primary 2. Similarly, when the ferromagnetic cylindrical core 3 is to enter the next cylindrical primary 2, it is also necessary to control the direction of the magnetic field generated by the next cylindrical primary 2, so that the ferromagnetic cylindrical core 3 can continue to accelerate in the same direction under the action of the magnetic field thrust. By repeating the aforementioned magnetic field changes, the ferromagnetic cylindrical iron core 3 can move at ultra-high speed within a long primary composed of multiple cylindrical primary 2 connected together. Furthermore, the direction and speed of movement of the ferromagnetic cylindrical iron core 3 within each cylindrical primary 2 can be flexibly controlled by changing the corresponding current direction and current magnitude through an external control system.

[0053] like Figure 5 The diagram shown is a schematic of the cylindrical primary 2 in this embodiment. The primary component in this embodiment employs wire cutting to directly form the current loop. The cylindrical primary 2 has a slotless structure and uniformly winds the coil winding 22. To prevent or reduce the heating problem caused by eddy currents within the magnetically interfered bias medium, the following method is used... Figure 6The high magnetic permeability and low electrical conductivity interference medium 23 shown is an intermediate skeleton made of materials such as permalloy or carbon steel. A coil winding 22 is wound around the intermediate skeleton to reduce the heating problem caused by eddy currents in the stacked structure. In this example, the cylindrical primary 2 can be Φ100mm×3000mm. The two end faces of the cylindrical primary 2 have end face connection holes 24 and side wall connection holes 25. Multiple end face connection holes 24 are used to connect adjacent cylindrical primary 2 sections; that is, bolts or connecting rods or other connecting fasteners that can achieve the connection function can be inserted into the end face connection holes 24. The side wall connection holes 25 are used to fix the cylindrical primary 2 to the primary bottom support 26 (i.e., the insulating support frame). The structure of the primary bottom support 26 is as follows: Figure 7 As shown, it has fixing holes 261 at both ends that can be fixed to the bottom of the groove of the I-shaped guide rail bracket 1, and a middle connecting hole 262 in the middle for fixing the cylindrical primary 2.

[0054] like Figure 2 As shown, the ferromagnetic cylindrical iron core 3 is a short secondary. This short secondary is made into a cylindrical shape using a ferromagnetic iron core with good magnetic permeability. In this example, its diameter is Φ85mm, which is smaller than the inner diameter of the cylindrical primary 2, so as to achieve non-contact operation with the cylindrical primary 2. A connector 33 is welded to the side of the ferromagnetic cylindrical iron core 3. The connector 33 is also welded to the external emitter 32 above. Since the external emitter 32 overlaps on the guide rail 11, the ferromagnetic cylindrical iron core 3 is suspended from the cylindrical primary 2 by the connector 33. The axisymmetric center of the cylindrical primary 2, namely the central axis of the ferromagnetic cylindrical iron core 3, is on the same straight line as the central axis of the cylindrical primary 2. The external emitter 32 and the guide rail 11 are connected by rolling bearings in the mounting grooves 31 at both ends of the lower surface of the external emitter, so that the external emitter 32 can slide on the guide rail 11, thereby further realizing the rigid fixation of the ferromagnetic cylindrical iron core 3. The ferromagnetic cylindrical iron core 3, the connector 33 and the external emitter 32 are combined into a whole secondary component to perform overall movement.

[0055] The aforementioned extracavitary motion body 32 can be replaced with other types of extracavitary motion bodies or expanded to include more extracavitary motion bodies, depending on the actual engineering situation.

[0056] like Figure 1 As shown, a position sensor 14 and a grating sensor 13 are also provided on the inner wall of the aforementioned guide rail 11. The position sensor 14 is used to detect the movement position of the entire secondary component, and the grating sensor 13 is used to detect the movement distance of the entire secondary component. The movement position information and movement distance information are ultimately transmitted to the external control system 4.

[0057] The aforementioned external control system 4 is used to upload the received position and movement distance information of the entire secondary component to the STM32F103 microcontroller. Through cascaded PID control, given the feedback deviation, the built-in software calculates and processes the result to obtain the control voltage and generate a PWM signal with a specific duty cycle. This signal is then sent to the driver via optocoupler isolation, and finally controls the speed and position of the linear motor.

[0058] In this embodiment, all control lines of the cylindrical primary 2 converge to the external control system 4, which completes a series of controls for any one of the cylindrical primary 2. When a control signal is input, the external moving body on the linear motor drive device obtains electromagnetic thrust and moves rapidly from one side of the linear motor to the other inside the multiple cylindrical primarys connected end to end, thereby realizing the function of electromagnetic catapult.

[0059] The working principle of the linear motor drive device in this embodiment is as follows:

[0060] Combination Figure 5 After the cylindrical primary 2 receives current, the coil winding generates a magnetic field surrounding the cylindrical primary 2. This magnetic field is positive. For the secondary component, the magnetic field between the S and N poles of the cylindrical primary 2 is half thrust and half repulsive. Through the positive electromagnetic thrust F, the secondary component can be propelled to the center of the magnetic field of the cylindrical primary 2. Then, the direction of the magnetic field is changed by the external control system 4 to generate a reverse magnetic field. Under the electromagnetic force generated by the reverse magnetic field, the secondary component continues to move forward. When it reaches the next section of the cylindrical primary, the aforementioned magnetic field change is repeated, so that under the continuous thrust acceleration, the external emitter 32 is continuously accelerated and ejected by the ferromagnetic cylindrical iron core 3. The magnitude of the aforementioned electromagnetic thrust satisfies the formula:

[0061] F = NBIL(1)

[0062] The input current I of a single cylindrical primary 2 is 5A, L is the length of the cylindrical primary 2, N is the number of turns of the coil winding on the cylindrical primary 2, and B is the magnetic field strength generated inside the cylindrical primary 2. During the operation of the motor, the coil winding on a single cylindrical primary 2 provides a voltage of 24V and a current of 5A-10A. If the number of coil turns is more, the required current is greater and the thrust generated is stronger. Therefore, the aforementioned current magnitude can be changed. The thrust change curve is a "U"-shaped curve, generally showing a trend of first decreasing and then increasing.

[0063] Because this type of linear motor drive device has the characteristics of continuous thrust, fast launch speed and large starting acceleration, it solves the problem of thrust fluctuation in traditional linear motors. Therefore, this type of linear motor drive device can be applied to electromagnetic assisted launch, so that large objects can obtain high-speed driving power and achieve rapid launch or start-up.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A variable stroke cylindrical linear motor drive device, characterized in that, Includes primary components, secondary components, and I-beam guide rail brackets (1), wherein: The primary component includes at least one cylindrical primary (2), and a through groove (21) is provided on the side wall of the cylindrical primary (2) along the central axis direction, so that the end face of the cylindrical primary (2) is an open circle; The I-shaped guide rail bracket (1) is symmetrically provided with guide rails (11), and grooves (12) are provided between the guide rails (11). The cylindrical primary (2) is fixed in the grooves (12), and the through groove (21) faces upward; the central axis of the cylindrical primary (2) is parallel to the direction of the guide rails (11); The secondary component includes a ferromagnetic cylindrical iron core (3) and an external emitter (32). The external emitter (32) is disposed above the through slot (21) and connected to the guide rail (11). A connector (33) is provided in the through slot (21). The lower end of the connector (33) is connected to the ferromagnetic cylindrical iron core (3), and the upper end of the connector (33) is connected to the external emitter (32), so that the ferromagnetic cylindrical iron core (3) is suspended inside the cylindrical primary (2). The cylindrical primary (2) can be connected to an external control system (4). When the external control system (4) powers the cylindrical primary (2), the cylindrical primary (2) can generate a positive magnetic field and a reverse magnetic field. Under the action of the positive magnetic field and the reverse magnetic field, the ferromagnetic cylindrical iron core (3) can drive the external emitter (32) along the central axis of the cylindrical primary (2) from any end of the cylindrical primary (2) to the other end of the cylindrical primary (2).

2. The variable stroke cylindrical linear motor drive device as described in claim 1, characterized in that, When there are two or more cylindrical primary (2) ...

3. The variable stroke cylindrical linear motor drive device as described in claim 2, characterized in that, The connected cylindrical primary (2) are either abutting or separated.

4. A variable stroke cylindrical linear motor drive device as described in any one of claims 1 or 2, characterized in that, The cylindrical primary (2) includes a cylindrical permanent magnet and a coil winding (22). The cylindrical permanent magnet has a through groove (21) on its side parallel to its central axis. The coil winding (22) is wound around the cylindrical permanent magnet in the circumferential direction until it completely covers the cylindrical permanent magnet, forming a cylindrical primary (2) with the through groove (21).

5. A variable stroke cylindrical linear motor drive device as described in claim 4, characterized in that, The coil winding (22) is a single-layer coil winding or a multi-layer coil winding composed of multiple turns of coil tightly attached together.

6. The variable stroke cylindrical linear motor drive device as described in claim 5, characterized in that, When there are two or more cylindrical primary (2) primary units, the number of turns of the coil windings of adjacent cylindrical primary (2) primary units may be the same or different.

7. A variable stroke cylindrical linear motor drive device as described in claim 5, characterized in that, When there are two or more cylindrical primary (2) primary units, the number of winding layers of the coil windings of adjacent cylindrical primary (2) primary units may be the same or different.

8. A variable stroke cylindrical linear motor drive device as described in claim 4, characterized in that, The cylindrical permanent magnet is made of an interference medium with high magnetic permeability and low electrical conductivity to prevent eddy current heating.

9. A variable stroke cylindrical linear motor drive device as described in claim 1, characterized in that, The two ends of the connector (33) are respectively welded to the external emitter (32) and the ferromagnetic cylindrical iron core (3). When the ferromagnetic cylindrical iron core (3) moves, the connector (33) does not contact the side wall of the through groove (21).

10. A variable stroke cylindrical linear motor drive device as described in claim 1, characterized in that, The linear motor drive device also includes a position sensor (14), which is used to detect the movement position of the secondary component and transmit the movement position information to the external control system (4).

11. A variable stroke cylindrical linear motor drive device as described in claim 10, characterized in that, The linear motor drive device also includes a grating sensor (13), which is used to detect the movement distance of the secondary component and transmit the movement distance to the external control system (4).

12. A variable stroke cylindrical linear motor drive device as described in claim 1, characterized in that, The external control system (4) is individually connected to each cylindrical primary (2) and is used to provide each cylindrical primary (2) with a current of the same or different magnitude.

13. A variable stroke cylindrical linear motor drive device as described in claim 1, characterized in that, The cylindrical primary (2) is provided with a connecting structure on both ends. When the primary component includes multiple cylindrical primary (2), adjacent cylindrical primary (2) are connected by the connecting structure arranged opposite to each other.

14. A variable stroke cylindrical linear motor drive device as described in claim 1, characterized in that, An insulating support frame is also provided between the cylindrical primary (2) and the groove (12). The thickness of the middle part of the insulating support frame is greater than the thickness of its two ends. The cylindrical primary (2) is fixed in the middle position of the insulating support frame, and the two ends of the insulating support frame are fixed on the groove (12).

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