Research On Permanent Magnet Linear Synchronous Motor Design

In conventional linear driving applications, original force is generated from rotary motor, so transmission devices is need, which causes large sum of energy loss, friction noise and brings out complicated maintenances.The introduction of linear motor targets at these problems, being able to directly convert electrical energy to linear moving, linear motor has gradually replaced rotary motor in linear driving applications such as lathe driving and integrated circuit assembly.Since the introduction of concept in mid 19th century, undergone four periods of breed, experiment, development and application, with virtue of power electronics and maturing controlling techniques, linear motor has been widely used in various fields such as production, transportation, etc.Similar to rotary motor, linear motor can be divided into various types according to working principles. Among these different types, linear stepping motor, linear synchronous motor and linear induction motor receive most focus, usually linear stepping motor is utilized in applications demand high precision, such as semi-conductor industry, while the later two often go with large and continuous thrust applications, such as lathe. Linear synchronous motor, especially permanent magnet ones, receive more favor for larger thrust per area unit and higher efficiency, and the construction of motor can be simplified due to the absence of exciting armature. On the other hand, abundant lanthanon in our country provides vast space for this kind of motor.To be a new type of motor, there is no enough systematic designing method for permanent magnet linear synchronous motor in our country, especially for the armature, the conventional way bases on rotary motor, using lapped dual-layer coil for example, which will bring about unsatisfactory results, such as too many lead in slot, hard to serialize, etc, and it gives fluctuate thrust when performing.For eliminating problems mentioned above, this paper proposes a new kind of design method for permanent magnet synchronous motor. Basing on idea of'Unit motor', we use single layer concentric coil in mover armature, and alter the amount and way of arrangement of the unit according to the change of target output thrust, no need to re-arrange the coil in the armature, so, complicated task of coil design can be avoided, which simplified the work of motor design. At the same time, single layer construction offers more convenience for production and heat dispersion.Finishing design work of the motor, we use finite element method software for electromagnetic analysis MagNet manufactured by a Canadian corporation Infolytica to simulate the performance, obtaining thrust-time curve and back-EMF curve, as the results show, new motor gives more smooth thrust, which proves superiority of the new method.