阅读说明：本技术 一种初级halbach永磁型直线电机 (Primary halbach permanent magnet type linear motor ) 是由 卢琴芬 沈燚明 于 2019-09-20 设计创作，主要内容包括：本发明公开了一种初级halbach永磁型直线电机,其短初级包括电枢铁芯、电枢绕组和halbach永磁阵列；电枢绕组为集中式开绕组结构,可通入直流偏置型三相正弦电流,halbach永磁阵列由两种充磁方向的永磁体构成,其中一种永磁体的充磁方向垂直于短初级的运动方向且在相邻电枢齿处极性相反,另一种永磁体的充磁方向平行于短初级的运动方向且在相邻电枢槽口处极性相反。本发明电机既能够使磁极与电枢都集中在短初级一侧,不需要采用分立部件结构且永磁体不被线圈包围,大大降低系统成本和永磁体的退磁风险,而且采用halbach永磁阵列结构可以发挥聚磁效应,进一步提高推力密度,此外增加了直流励磁磁场,实现气隙磁场可调。(The invention discloses a primary halbach permanent magnet type linear motor, wherein a short primary comprises an armature core, an armature winding and a halbach permanent magnet array; the armature winding is of a centralized open winding structure and can be fed with direct current bias type three-phase sinusoidal current, the halbach permanent magnet array is composed of permanent magnets in two magnetizing directions, wherein the magnetizing direction of one permanent magnet is perpendicular to the moving direction of the short primary and opposite in polarity at the position of the adjacent armature teeth, and the magnetizing direction of the other permanent magnet is parallel to the moving direction of the short primary and opposite in polarity at the position of the adjacent armature notches. The motor can concentrate the magnetic poles and the armature on one side of the short primary without adopting a discrete component structure, and the permanent magnet is not surrounded by the coil, so that the system cost and the demagnetization risk of the permanent magnet are greatly reduced, the halbach permanent magnet array structure can play a role in magnetic convergence, the thrust density is further improved, and in addition, a direct-current excitation magnetic field is added, and the adjustability of an air gap magnetic field is realized.)

1. A primary halbach permanent magnet type linear motor comprises a short primary and a long secondary; the method is characterized in that:

The short primary comprises an armature core, an armature winding and a halbach permanent magnet array, the armature core is of an integral stamped sheet type tooth groove structure, and the armature winding is wound on each armature tooth;

The halbach permanent magnet array is composed of a plurality of permanent magnet units in parallel, each permanent magnet unit is embedded at an armature notch corresponding to an armature core, adjacent permanent magnet units are isolated through convex structures on corresponding armature teeth, the permanent magnet units are formed by attaching a permanent magnet A1, a permanent magnet B and a permanent magnet A2 side by side from left to right, the permanent magnet B is over against the armature notch, the magnetizing direction is parallel to the moving direction of a short primary, and the polarities of the permanent magnets B in the two adjacent permanent magnet units are opposite; permanent magnets A1 and A2 are respectively arranged on armature teeth on two sides of an armature slot, the magnetizing direction is perpendicular to the moving direction of the short primary, and the permanent magnets A1 and A2 in the same permanent magnet unit are opposite in polarity.

2. the primary halbach permanent magnet-type linear motor of claim 1, wherein: the long secondary is a laminated core with an integral punching sheet type tooth socket structure, a tooth socket of the laminated core faces to a tooth socket of the armature core, and a certain air gap is reserved between the long secondary and the armature core.

3. The primary halbach permanent magnet-type linear motor of claim 1, wherein: for any permanent magnet unit, the permanent magnet A1 and the permanent magnet A2 of the left adjacent permanent magnet unit are arranged on the same armature tooth and have the same polarity, the permanent magnet A2 and the permanent magnet A1 of the right adjacent permanent magnet unit are arranged on the same armature tooth and have the same polarity, and therefore, the permanent magnets on the adjacent armature teeth have opposite polarities.

4. The primary halbach permanent magnet-type linear motor of claim 1, wherein: the armature winding adopts a centralized open winding structure, and direct current bias type three-phase sinusoidal current is introduced during work, namely direct current and three-phase sinusoidal alternating current are introduced simultaneously.

5. The primary halbach permanent magnet-type linear motor of claim 4, wherein: the direct current in the armature winding is used for generating a direct current excitation magnetic field, and when the direct current excitation magnetic field is used for increasing magnetism, the direction of the direct current excitation magnetic field is opposite to that of the magnetic field of the permanent magnet unit in the short primary, and the direction of the direct current excitation magnetic field is the same in the long secondary; when used for demagnetization, the dc excitation field is in the same direction as the field of the permanent magnet unit in the short primary and opposite in the long secondary.

6. The primary halbach permanent magnet-type linear motor of claim 1, wherein: the number of long secondary teeth in the region opposite to the short primary teeth is 1-2 more than that of the short primary teeth.

7. The primary halbach permanent magnet-type linear motor of claim 1, wherein: the armature teeth at two ends of the armature core are in irregular shapes, namely, the outer iron cores at two ends of the armature teeth are partially cut off.

8. The primary halbach permanent magnet-type linear motor of claim 1, wherein: both ends of the armature core and the bottom of the long secondary side back to the armature core are respectively provided with a welding mounting hole, namely the armature core adopts a fixing mode of welding the bottom and the end.

Technical Field

The invention belongs to the technical field of linear motors, and particularly relates to a primary halbach permanent magnet type linear motor.

background

The permanent magnet linear motor has the advantages of both the permanent magnet motor and the linear motor, and can directly convert electric energy into mechanical energy of linear motion without an intermediate linkage part. Therefore, the permanent magnet linear synchronous motor has the remarkable advantages of simple structure, high speed, high precision, high efficiency, high thrust and the like, and is widely applied to the fields of high-speed numerical control machine tools, semiconductor processing, vertical lifting conveying systems, high-speed logistics systems and the like.

The working principle of the permanent magnet linear motor is as follows: when the armature winding is electrified with alternating current, an armature magnetic field is generated in the air gap, and meanwhile, the permanent magnetic pole generates an excitation magnetic field in the air gap, and the armature magnetic field and the permanent magnetic excitation magnetic field jointly form an air gap magnetic field; when the magnetic field generator is started, the magnetic pole or the armature is dragged, and the armature traveling wave magnetic field and the permanent magnet excitation magnetic field are relatively static, so that the current in the armature winding generates electromagnetic thrust under the action of the air gap magnetic field; if the armature is fixed, the magnetic pole is drawn into the synchronous linear motion under the action of thrust; otherwise, the armature is drawn to move linearly synchronously.

Aiming at the field of high-speed logistics systems, because the moving stroke is long (from several meters to dozens of meters), the permanent magnet linear motor has a great limitation on the popularization and application in cost, and the overall cost is very high no matter a long armature or a long magnetic pole structure is adopted. In order to reduce the cost, the conventional method is to concentrate both the permanent magnet and the armature on one side of the armature as a short primary, and the secondary is formed of only a laminated core as a long stator, i.e., a primary permanent magnet type linear motor.

The primary permanent magnet type linear motor mainly comprises the following types:

firstly, the method comprises the following steps: switch flux linkage permanent magnet linear motor.

This structure places the permanent magnet in armature tooth intermediate position, and its permanent magnet quantity is less, and armature length is shorter, can greatly reduced at long stroke application occasion cost, but also brings new problem: 1. the armature core is composed of a plurality of discrete components, and is difficult to process and install; 2. the groove area and the permanent magnet are mutually restricted, and the thrust density is limited; 3. the permanent magnet is surrounded by the armature winding, and the heat dissipation condition is too poor; 4. the air gap magnetic field is difficult to adjust, and the weak magnetic speed expansion range is limited.

II, secondly: magnetic flux reverse type permanent magnet linear motor.

According to the structure, the permanent magnet is placed on the tooth surface of the armature core (close to an air gap), the using amount of the permanent magnet is small, the length of the armature is short, the cost is greatly reduced in a long-stroke application occasion, and a new problem is caused: 1. because the magnetic circuits are connected in series, the armature magnetic circuit needs to pass through the permanent magnet, so that the equivalent air gap of the armature magnetic circuit is enlarged, and the thrust density is limited; 2. the armature magnetic field needs to pass through the permanent magnet, and when the armature current is large, the permanent magnet has very high demagnetization risk; 3. the air gap magnetic field is difficult to adjust, and the weak magnetic speed expansion range is limited.

Thirdly, the method comprises the following steps: a primary yoke permanent magnet type linear motor.

This structure places the yoke portion between the adjacent armature tooth of armature core to the permanent magnet, and its permanent magnet quantity is less, and armature length is shorter, at long stroke application occasion cost greatly reduced, also brings new problem equally: 1. because the magnetic circuits are connected in series, the armature magnetic circuit needs to pass through the permanent magnet, and the permanent magnet has very high demagnetization risk; 2. the primary iron core is composed of a plurality of discrete components, and is difficult to process and install; 3. the yoke part of the motor is very easy to saturate, and the thrust density is limited; 4. the air gap magnetic field is difficult to adjust, and the weak magnetic speed expansion range is limited.

Disclosure of Invention

In view of the above, the invention provides a primary halbach permanent magnet type linear motor, which can not only concentrate a magnetic pole and an armature on one side of a short primary, but also greatly reduce the system cost and the demagnetization risk of a permanent magnet without adopting a discrete component structure, and can exert a magnetism gathering effect by adopting a halbach permanent magnet array structure, thereby further improving the thrust density, and in addition, increasing a direct-current excitation magnetic field and realizing the adjustability of an air gap magnetic field.

A primary halbach permanent magnet type linear motor comprises a short primary and a long secondary;

The short primary comprises an armature core, an armature winding and a halbach permanent magnet array, the armature core is of an integral stamped sheet type tooth groove structure, and the armature winding is wound on each armature tooth;

The halbach permanent magnet array is composed of a plurality of permanent magnet units in parallel, each permanent magnet unit is embedded at an armature notch corresponding to an armature core, adjacent permanent magnet units are isolated through convex structures on corresponding armature teeth, the permanent magnet units are formed by attaching a permanent magnet A1, a permanent magnet B and a permanent magnet A2 side by side from left to right, the permanent magnet B is over against the armature notch, the magnetizing direction is parallel to the moving direction of a short primary, and the polarities of the permanent magnets B in the two adjacent permanent magnet units are opposite; permanent magnets A1 and A2 are respectively arranged on armature teeth on two sides of an armature slot, the magnetizing direction is perpendicular to the moving direction of the short primary, and the permanent magnets A1 and A2 in the same permanent magnet unit are opposite in polarity.

Further, the long secondary is a laminated core with an integral punching sheet type tooth socket structure, a tooth socket of the laminated core faces to a tooth socket of the armature core, and a certain air gap exists between the long secondary and the armature core.

Further, for any permanent magnet unit, the permanent magnet a1 of the permanent magnet unit and the permanent magnet a2 of the left adjacent permanent magnet unit are set on the same armature tooth and have the same polarity, and the permanent magnet a2 of the permanent magnet unit and the permanent magnet a1 of the right adjacent permanent magnet unit are set on the same armature tooth and have the same polarity, so the permanent magnets on the adjacent armature teeth have opposite polarities.

Furthermore, the armature winding adopts a centralized open winding structure, and direct-current bias type three-phase sinusoidal current is introduced during work, namely direct current and three-phase sinusoidal alternating current are introduced simultaneously.

further, the direct current in the armature winding is used to generate a direct current excitation magnetic field, which, when used for magnetizing, is opposite in direction to the magnetic field of the permanent magnet unit in the short primary and the same in the long secondary; when used for demagnetization, the dc excitation field is in the same direction as the field of the permanent magnet unit in the short primary and opposite in the long secondary.

Further, the number of the long secondary teeth in the region opposite to the short primary teeth is 1-2 more than that of the short primary teeth.

preferably, the armature teeth at the two ends of the armature core are irregularly shaped, namely, a part of the outer iron core of the armature teeth at the two ends is cut off, so that the side end effect can be reduced, and the purpose of weakening the side end force is achieved.

Furthermore, welding mounting holes are formed in the two ends of the armature core and the bottom, back to the long secondary, of the armature core, namely the armature core is fixed in a mode that the bottom and the end are welded.

The short primary of the primary halbach permanent magnet type linear motor simultaneously comprises an armature and a magnetic pole part, the armature and the magnetic pole part are fixed on a mobile platform, the mobile platform obtains high-speed linear motion in a long stroke by driving the short primary, the advantages of the structure of the conventional primary excitation type permanent magnet linear motor are realized, and meanwhile, compared with the prior art, the primary halbach permanent magnet type linear motor has the following beneficial technical effects:

1. The invention concentrates the armature and the magnetic pole on the short primary, and the armature winding can input direct current exciting current, realizes the mixed excitation structure of electric excitation and permanent magnet common excitation, not only greatly reduces the length of the magnetic pole (armature), but also does not need to adopt discrete components, and is suitable for application occasions requiring long stroke, large thrust, high speed and low cost, such as a high-speed logistics system.

2. The halbach permanent magnet array has a magnetism gathering effect, the thrust density of the motor can be further improved, and the demagnetization risk of the permanent magnet is greatly reduced due to the adoption of a parallel magnetic circuit structure.

3. According to the invention, only a single set of armature winding is needed, a direct-current excitation magnetic field and an armature magnetic field can be generated simultaneously, and the direct-current excitation magnetic field can dynamically adjust an air gap magnetic field so as to adapt to different working conditions such as short-time large thrust, weak magnetic speed expansion and the like; the armature winding is the same as a common permanent magnet linear motor, and is convenient to process and low in cost.

4. the long secondary is formed by laminating the punching sheets with the tooth grooves, so that the cost is low, the processing and the installation are convenient, and the modularization is easy to realize.

Drawings

Fig. 1 is a schematic view of a first embodiment of a linear motor according to the present invention.

Fig. 2 is a schematic view of armature winding connection of a first embodiment of the linear motor according to the present invention.

Fig. 3 is a connection diagram of a driving circuit of a first embodiment of the linear motor according to the present invention.

Fig. 4 is a schematic view of the magnetic field direction of the linear motor during permanent magnet excitation.

Fig. 5 is a schematic view of the magnetic field direction during hybrid excitation of the linear motor of the present invention.

fig. 6 is a schematic structural view of an armature tooth at an end of a linear motor according to the present invention.

Fig. 7 is a schematic structural diagram of a conventional linear motor using a dc excitation winding.

Fig. 8 is a comparison between the performance of a conventional linear motor using a dc field winding and the performance of the present invention.

fig. 9 is a schematic view of armature winding connection of a second embodiment of the linear motor according to the present invention.

Fig. 10 is a connection diagram of a driving circuit of a second embodiment of the linear motor according to the present invention.

Fig. 11 is a schematic view of a third embodiment of the linear motor of the present invention.

Fig. 12 is a schematic diagram of a fourth embodiment of the linear motor of the present invention.

Detailed Description

In order to more specifically describe the present invention, the following detailed description is provided for the technical solution of the present invention with reference to the accompanying drawings and the specific embodiments.