High linearity limited rotation torque motor

Abstract

This invention belongs to the field of motor technology and discloses a high-linearity finite-angle torque motor, comprising a cylindrical rotor and a cylindrical stator, with the rotor housed within the stator. The stator includes N coils and N constant magnetic circuit channels, where N is an even number of at least 2. The rotor's magnet portion has N polarities. The N coils of the stator are evenly arranged circumferentially on the inner side of the stator, with adjacent coils separated by constant magnetic circuit channels. The ends of all coil frames and the ends of the constant magnetic circuit channels together form the rotor's rotational track. Adjacent stator coils have opposite polarities after being energized, and adjacent rotor magnets also have opposite polarities. This invention employs a special stator lamination structure, theoretically eliminating stator cogging torque within the motor's operating angle range, thus improving the linearity of the motor's output torque. Compared to traditional slotted finite-angle torque motors, the output torque fluctuation is reduced by more than 70%.

Description

Technical Field

[0001] This invention belongs to the field of motor technology and relates to a finite angle torque motor, specifically a high linearity finite angle torque motor. Background Technology

[0002] High linearity (high precision) finite angle torque motors are mainly used to drive infrared detection imaging mirrors. The linearity of their output torque and their dynamic response characteristics are directly related to the clarity and range of the imaging.

[0003] Traditional reluctance finite torque motors have a small effective working angle and a large rotor outer diameter, resulting in a small imaging range and poor imaging clarity for infrared detectors, such as CN103683769A and CN205753727U finite torque motors.

[0004] Traditional slotted finite-angle torque motors, such as CN205846888U and CN207426941U, have a large cogging torque due to the change in magnetic flux area with rotor position within the working angle range, resulting in poor linearity of output torque and poor image clarity. Traditional slotless finite-angle motors have a large rotor outer diameter, large moment of inertia, and small torque coefficient, leading to poor dynamic response and severely affecting the imaging clarity of infrared imagers. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a finite angle torque motor with a special lamination structure and magnetic circuit structure, thereby solving the issues of small operating angle in traditional reluctance finite angle torque motors, large cogging torque in slotted finite angle torque motors, and poor dynamic response in slotless finite angle torque motors.

[0006] The technical solution of this invention is:

[0007] A high linearity finite angle torque motor includes a cylindrical rotor and a cylindrical stator, with the rotor housed within the stator. The stator comprises a cylindrical body and N coils and N constant magnetic circuit channels mounted inside the body, where N is an even number of at least 2. The rotor's magnet portion has N polarities. The N coils of the stator are evenly arranged circumferentially on the inner side of the stator, with adjacent coils separated by constant magnetic circuit channels. The ends of the coil frames and the ends of the constant magnetic circuit channels together form the rotor's rotational track. On the stator, adjacent coils have opposite polarities after energization, and on the rotor, adjacent magnets have opposite polarities. The magnetic field generated by the rotor's magnets forms a closed-loop magnetic circuit through the constant magnetic circuit channels and the stator body. The stator's terminals are connected to an energizing direction switch.

[0008] Furthermore, when the motor is in the mechanical zero position, the midpoint of the rotor's magnet polarity corresponds to the position of the constant magnetic circuit channel, while the transition area between two adjacent magnets of different polarities corresponds to the position of the stator coils. When the stator coils are energized, they generate a magnetic field. The staggered arrangement of the magnetic field directions generated by all the coils produces a clockwise or counterclockwise electromagnetic pull on the rotor. After the rotor rotates to the required angle, the direction of the energizing current is switched, producing an electromagnetic pull in another direction of rotation on the rotor. By continuously switching the direction of the energizing current, the rotor can rotate within the stator at a limited angle to output torque.

[0009] Furthermore, the stator has a cylindrical structure, with the stator coil frame integrated with the stator body. The ends of the coil frame extend outward to form an arc surface that matches the rotor. The outward extension of the ends of the coil frame serves two purposes: firstly, to fix the coil, and secondly, to facilitate the convergence of the magnetic circuit.

[0010] Furthermore, the constant magnetic circuit channel is integrated with the stator cylinder, the height of the constant magnetic circuit channel is the same as the coil frame, and the end of the constant magnetic circuit channel is an arc surface that matches the rotor.

[0011] Furthermore, the constant magnetic circuit channel, coil frame, and cylinder are integrated stator lamination structures, and the material of the stator lamination structure is 1J22.

[0012] Furthermore, the rotor core is a cylindrical structure, and a cylindrical bushing is provided outside the rotor core. This rotor design achieves the highest torque accuracy.

[0013] Furthermore, the rotor core has a square column structure, with the polarity of the rotor core located on the surface of the square edge. A cylindrical bushing is provided outside the rotor core, and the bushing contains a square cavity that fits the rotor core. This rotor design makes the rotor structure easy to manufacture, and the fixing method between the rotor and the bushing is stable and reliable.

[0014] Furthermore, the rotor core has a quasi-square prism structure, with the polarity of the rotor core located on the surface of the square edge. The four right angles of the square prism are rounded. A cylindrical bushing is provided outside the rotor core, and the bushing has a cavity that matches the shape of the rotor core. This rotor design achieves both high precision in torque and stable and reliable fixation.

[0015] The advantages of this invention are:

[0016] 1. This invention is a slotted finite angle torque motor, which adopts a special stator lamination structure. The theoretical maximum rotation angle of this invention is the width of the coil frame, which is generally 10° to 12°. Since the rotation will not exceed the range of the sawtooth, the magnetic flux will not change significantly due to the rotation of the rotor. Therefore, theoretically, the motor eliminates stator cogging torque within the working angle range, improves the linearity of the motor output torque, and reduces the output torque fluctuation by more than 70% compared with traditional slotted finite angle torque motors.

[0017] 2. The principle of this invention can be applied to both rotary motors and linear motors, making it highly applicable and structurally stable.

[0018] 3. This invention provides various rotor structure forms for rotating electric motors, which is beneficial to balance the high precision of rotational torque and the structural stability of the rotor.

[0019] 4. Compared with traditional reluctance limited-angle motors, the effective working angle of the motor is increased by about 30%, which can effectively improve the imaging range of infrared imagers.

[0020] 5. Compared with traditional slotless limited-angle motors, this structure can effectively improve the air gap magnetic flux density of the motor, thereby increasing its torque density. It can effectively improve the dynamic response characteristics of the motor, improve the imaging accuracy of the infrared imager, and effectively reduce the size of the motor under the same output torque conditions. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the finite angle motor of the present invention;

[0022] Figure 2 This is a schematic diagram of the limited-angle motor of the present invention rotating a certain angle after the coil is energized;

[0023] Figure 3 This is a schematic diagram of the limited-angle motor of the present invention rotating by an angle on the other side after the coil is energized;

[0024] Figure 4 This is a schematic diagram of the mechanical zero-position magnetic field of the finite-angle motor of the present invention;

[0025] Figure 5 This is a schematic diagram of the magnetic field of the finite angle motor coil after it is energized according to the present invention;

[0026] Figure 6 These are two other rotor structure forms of the present invention;

[0027] Figure 7 This is a schematic diagram of the overall structure of the rotary motor of the present invention;

[0028] Figure 8This is a schematic diagram of the maximum operating range of a traditional limited-angle motor;

[0029] Figure 9 This is a schematic diagram of the 1A current output torque of the present invention;

[0030] Figure 10 A schematic diagram of the output torque of a traditional slotted finite angle motor with a current of 1A;

[0031] Figure 11 This is a schematic diagram of the output torque of a reluctance finite angle motor with a current of 1A.

[0032] Wherein, 1—rotor, 2—stator, 3—shaft sleeve, 4—rotor yoke, 5—casing, 21—constant magnetic circuit channel, 22—coil. Detailed Implementation

[0033] This section describes embodiments of the present invention, used to explain and illustrate the technical solutions of the present invention. Unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0034] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating directions or positional relationships, are given in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or device referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include more than one of those features. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integrated connections; they can refer to mechanical connections or point connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] The core structure of this invention lies in the stator lamination structure, where the stator coil frame, stator body, and constant magnetic circuit channel are integrated into a single unit. This structure, combined with the interlaced coils and magnets, forms a highly ingenious and stable magnetic circuit structure. The stator lamination structure confines the magnetic field generated by the rotor magnets within itself. When the coils are energized, a new magnetic field is generated, disrupting the original magnetic balance and generating magnetic pull that causes the rotor to rotate. Meanwhile, the stator lamination structure continues to concentrate the magnetic field generated by the coils and rotor magnets, ensuring that the maximum theoretical operating angle of the rotor does not exceed the width range of a single coil. This prevents drastic changes in magnetic flux with rotor movement, resulting in minimal torque fluctuations in the motor.

[0038] This invention specifically relates to a high-linearity finite-angle torque motor, comprising a cylindrical rotor 1 and a cylindrical stator 2, with the rotor 1 housed within the stator 2. The stator 2 includes N coils and N constant magnetic circuit channels, where N is at least 2 and is an even number. The magnet portion of the rotor 1 has N polarities. The N coils of the stator 2 are evenly arranged circumferentially on the inner side of the stator 2, with adjacent coils separated by constant magnetic circuit channels. The ends of the coil frames and the ends of the constant magnetic circuit channels together form the rotational track of the rotor 1. On the stator 2, adjacent coils have opposite polarities after being energized; on the rotor 1, adjacent magnets have opposite polarities. The magnetic field generated by the magnets of the rotor 1 forms a closed-loop magnetic circuit through the constant magnetic circuit channels and the stator 2 cylinder. The terminals of the stator 2 are connected to AC power or an energizing direction switch.

[0039] When the motor is in the mechanical zero position, the midpoint of the magnet polarity of rotor 1 corresponds to the position of the constant magnetic circuit channel. At this time, the intersection point between the magnet polarities of rotor 1 corresponds to the position of the coil of stator 2. After the coil of stator 2 is energized, it generates a magnetic field. The staggered arrangement of the magnetic field directions generated by all the coils generates a clockwise or counterclockwise electromagnetic pull on rotor 1. After rotor 1 rotates to the required angle, the direction of the energizing current is switched, generating an electromagnetic pull on rotor 1 in another rotation direction. By continuously switching the direction of the energizing current, rotor 1 can rotate within stator 2 at a limited angle to output torque.

[0040] Stator 2 has a cylindrical structure, and the coil frame of stator 2 is integrated with the cylinder body of stator 2. The ends of the coil frame are extended outward to form an arc surface that matches the rotor. The outward extension of the ends of the coil frame serves two purposes: to fix the coil and to facilitate the convergence of the magnetic circuit.

[0041] The constant magnetic circuit channel is integrated with the cylinder of stator 2. The height of the constant magnetic circuit channel is the same as that of the coil frame, and the end of the constant magnetic circuit channel is an arc surface that matches the rotor.

[0042] The stator's coil frame, cylinder, and constant magnetic circuit channel are an integrated stator lamination structure, and its material is 1J22.

[0043] The core of rotor 1 is a cylindrical structure, and a cylindrical bushing 3 is provided outside the core of rotor 1. Rotor 1 with this design has the highest torque accuracy.

[0044] like Figure 6 As shown, the core of rotor 1 has a square column structure, with the polarity of the core located on the square side. A cylindrical bushing 3 is provided outside the core, and the bushing 3 has a square cavity that fits the core. This design of rotor 1 makes its structure easy to manufacture, and the fixing method between the rotor and the bushing is stable and reliable. The core of rotor 1 has a square column structure, with the polarity of the core located on the square side. The four right angles of the square column are rounded. A cylindrical bushing 3 is provided outside the core, and the bushing 3 has a cavity that fits the shape of the core. This design of rotor 1 achieves both high precision in torque and stable and reliable fixing.

[0045] The principle of this invention is to utilize a special stator lamination structure, namely, the constant magnetic circuit channel of stator 2, the stator coil frame, and the stator body form a closed-loop magnetic circuit channel. Under the action of the magnetic field generated by the magnets of rotor 1, these magnetic circuit channels concentrate and control the magnetic field generated by the magnets within the channels of the stator lamination structure, forming a closed-loop magnetic circuit. In this structure, due to the arrangement of coils with alternating polarities, an alternating magnetic field is generated after energization, thereby forming an electromagnetic pull on the rotor. The coil frame also participates in the large magnetic circuit closed loop. Combined with the original magnetic circuit, this prevents the rotor from rotating over a large range, but rather within the width of a single coil frame, which is the maximum theoretical operating range of this type of motor. Changing the current direction before the rotor rotates outside the maximum theoretical operating range can regularly change the direction of the magnetic field, thereby generating a regularly changing electromagnetic pull to make the motor rotor rotate regularly and within a limited range.

[0046] Based on the above principles of the present invention, the present invention can be practically applied to rotary motors and linear motors.

[0047] This invention uses a rotary electric motor as an example, and exemplifies a structure with four coils, such as... Figures 1 to 7 As shown, it includes a stator 2 housed in the housing 5, and a rotor housed in the stator 2.

[0048] The stator 2 winding consists of four coils, which are evenly arranged at 90° intervals. A constant magnetic circuit channel is provided between every two coils.

[0049] In the initial state, i.e. the mechanical zero position state: after the four coils are energized in the positive direction, the magnetic field directions generated are up, left, down and right respectively in clockwise order. That is, the magnetic field directions generated by the two longitudinal coils are both outward, the magnetic field directions generated by the two transverse coils are both inward, and the magnetic field directions generated by the two adjacent coils are opposite after being energized.

[0050] like Figure 1 As shown, the four coil electromagnets are separated by constant magnetic circuit channels, that is, there are also four constant magnetic circuit channels. The rotor magnet of the motor has four polarities, which are evenly and symmetrically distributed and spaced apart. The magnetic field generated by the four polarities forms a closed-loop magnetic circuit under the convergence of the four constant magnetic circuit channels, which prevents the outer part of the coil from participating in the large closed-loop magnetic circuit.

[0051] If it's a two-coil structure, the magnetic fields generated by the coils after energization can both point inwards or both outwards; in short, the magnetic fields generated by adjacent coils after energization should be in opposite directions. The same logic applies to stators with six or eight coils. Of course, the corresponding rotor must also have a corresponding number of polarities. The number of coils determines the motor's rotation angle; the more coils, the smaller the maximum theoretical rotation angle, but also the smaller the theoretical fluctuation.

[0052] In this design, the positions of the four constant magnetic circuit channels correspond to the polarity positions of the rotor. At this time, the motor is in mechanical zero position, and the angle between the rotor polarity centerline and the coil is 45°; the magnetic field state is as follows. Figure 4 As shown, the magnetic field generated by the magnet extends from one constant magnetic circuit channel to its adjacent constant magnetic circuit channel to another magnet.

[0053] After power is applied:

[0054] like Figure 2 , Figure 3 and Figure 5 As shown, according to the principle of the spiral, the coil generates a predetermined magnetic field. The newly generated magnetic field changes the original magnetic balance. At this time, the coil frame participates in the large closed loop of the magnetic field. The magnetic field generated by the magnet flows from the coil frame to the constant magnetic circuit channel, causing the rotor to move according to the principle of minimum magnetic reluctance, such as clockwise or counterclockwise. When the required rotation angle is reached, the direction of current is changed, causing the rotor to move back according to the principle of minimum magnetic reluctance again. This process repeats, forming a high-speed motor with finite rotation angle reciprocating motion. Since the magnetic circuit channel becomes the connection between the coil frame and the adjacent constant magnetic circuit channel, the interval angle between them is smaller than the adjacent angle between the two polarities of the magnet, resulting in a very small rotation angle. At this time, the theoretical maximum operating angle of the motor is the width of a single coil frame.

[0055] The maximum operating range of a traditional finite angle motor is as follows: Figure 8 As shown, its maximum working angle is ±(90°-A) / 2. The disadvantage of this structure is that it has a large cogging torque, which affects the linearity of the motor output torque.

[0056] Figures 9 to 11This is a schematic diagram comparing the output torque of the present invention with several traditional methods. As shown in the figure, under the conditions of the same motor volume, the same input current, and similar output torque, the peak torque of the present invention is 0.628, while the peak torque of the traditional slotted finite angle motor is 2.2, and the peak torque of the traditional reluctance finite angle motor is 2.7. The torque fluctuation of the present invention obviously has the advantage of smaller fluctuation compared to the two traditional finite angle motors, and is more suitable for products with low requirements for motor torque fluctuation, such as infrared detection imaging mirrors.

Claims

1. A high linearity finite angle torque motor, characterized in that, The device includes a cylindrical rotor (1) and a cylindrical stator (2), with the rotor (1) located inside the stator (2). The stator (2) includes N coils and N constant magnetic circuit channels, where N is an even number. The magnets of the rotor (1) have N polarities. The N coils of the stator (2) are evenly arranged circumferentially on the inner side of the stator (2), and adjacent coils are separated by constant magnetic circuit channels. The ends of the coil frames and the ends of the constant magnetic circuit channels together form the rotation track of the rotor (1). On the stator (2), the polarities of adjacent coils are opposite after being energized. On the rotor (1), the polarities of adjacent magnets are opposite. The magnetic field generated by the magnets of the rotor (1) forms a closed-loop magnetic circuit through the constant magnetic circuit channels and the cylinder of the stator (2). The terminals of the stator (2) are connected to an energizing direction switch. When the motor is in the mechanical zero position, the midpoint of the polarity of the magnet of the rotor (1) corresponds to the position of the constant magnetic circuit channel, and the transition area between two adjacent different polarities of the magnet of the rotor (1) corresponds to the position of the coil of the stator (2); after the coil of the stator (2) is energized, a magnetic field is generated. The magnetic field directions generated by all the coils are staggered, which generates a clockwise or counterclockwise electromagnetic pull on the rotor (1); after the rotor (1) rotates to the required angle, the direction of the energizing current is switched, which generates another electromagnetic pull on the rotor (1) in another rotation direction; by continuously switching the direction of the energizing current, the rotor (1) rotates within the stator (2) at a limited angle to output torque.

2. The high linearity finite angle torque motor according to claim 1, characterized in that, The stator (2) is a cylindrical structure. The coil frame of the stator (2) is integrated with the cylindrical wall of the stator (2). The end of the coil frame is extended outward to form an arc surface that matches the rotor.

3. A high linearity finite angle torque motor according to claim 2, characterized in that, The constant magnetic circuit channel is integrated with the cylindrical wall of the stator (2). The height of the constant magnetic circuit channel is the same as that of the coil frame. The end of the constant magnetic circuit channel is an arc surface that matches the rotor.

4. A high linearity finite angle torque motor according to claim 1, characterized in that, The constant magnetic circuit channel and coil frame are integrated stator lamination structures, and the material of the stator lamination structure is 1J22.

5. A high linearity finite angle torque motor according to claim 1, characterized in that, The core of the rotor (1) is a cylindrical structure, and a cylindrical bushing (3) is provided outside the core of the rotor (1).

6. A high linearity finite angle torque motor according to claim 1, characterized in that, The core of the rotor (1) is a square column structure. The polarity of the core of the rotor (1) is located on the surface of the square edge. The core of the rotor (1) is provided with a cylindrical bushing (3). The bushing (3) has a square cavity that matches the core of the rotor (1).

7. A high linearity finite angle torque motor according to claim 1, characterized in that, The core of the rotor (1) is a square column structure. The polarity of the core of the rotor (1) is located on the surface of the square edge. The four right angles of the square column are rounded. A cylindrical bushing (3) is provided outside the core of the rotor (1). The bushing (3) has a cavity that matches the shape of the core of the rotor (1).

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