Marilia Amaral da Silveira

Development of a New Electromagnetic Planar Actuator

Abstract This paper depicts a new electromagnetic planar actuator. It includes a slotless stationary plane annature, orthogonal windings and a wireless mover with two permanent magnets. The planar actuator develops movement over a plane surface as a result of the interaction between the air gap magnetic flux and current established through the orthogonal multiphase windings of the annature circuit The actuator was analysed by means of the finite element method The actuator can be used in mechatronic systems that require movement on a plane in two directions, e.g. semiconductor wafers and printed circuits movers, and pieces machined by nwnerically controlled (NC) machines.

Static Characterization of the Driving, Normal and Stall Forces of a Double-Sided Moving-Permanent Magnet-Type Planar Actuator Based on Orthogonal Planar Windings

This work presents a study of the traction, normal and stall forces in a two-sided planar actuator with orthogonal planar windings and a mover that comprises two cars magnetically coupled to each other through two pairs of permanent magnets (PMs). There is no ferromagnetic armature core because of the permanent magnets array in the mover and orthogonal traction forces can be generated in order to move both cars jointly in any direction on a plane. The stall force is the minimal force necessary to break up the magnetic coupling between the two cars. When one of the cars is subjected to an external force through the x- or y-axis, the cars can become out of alignment with respect to each other and the planar actuator cannot work properly. The behavior of the forces was modelled by numerical and analytical methods and experimental results were obtained from tests carried out on a prototype. The average sensitivity of the measured static propulsion planar force along either axis is 4.48 N/A. With a 20-mm displacement between the cars along the direction of the x-axis and no armature current, a magnetic stall force of 17.26 N is produced through the same axis in order to restore the alignment of the two cars.

AVALIAÇÃO ECONÔMICA DA SUBSTITUIÇÃO DO PROCESSO DE MICROFUSÃO PELA TECNOLOGIA DO PÓ APLICADA AO MECANISMO IMPRESSOR

This work presents a study of the application of new manufacturing processes and the use of new materials for the production of a component of print heads employed in dot matrix printers manufactured by industry. The manufacturer employs a ferromagnetic component produced by casting, which has many steps of manufacturing until the final assembly. During these steps, there is a high rejection rate of parts. The development of a new production process of the ferromagnetic component by powder metallurgy, with the employment of other ferromagnetic alloys and a new geometric model are extremely important to reduce costs of manufacturing. The study involves the production and the evaluation of the performance of samples of ferromagnetic alloys obtained by the powder metallurgy process and the comparison of the results with those generated by samples produced by the process of casting. The replacement of the manufacturing process will propitiate to the manufacturer a reduction of about 36% in manufacturing costs, allowing a more competitive marketing. Keywords: Powder metallurgy; dot-matrix print head; ferromagnetic alloy; manufacturing costs.

Theoretical and Experimental Analysis of an Induction Planar Actuator with Different Secondaries—A Planar Driver Application for Metallic Surface Inspection

This paper presents a study on an induction planar actuator concept. The device uses the same principles as a linear induction motor in which the interaction between a travelling magnetic field and a conducting surface produces eddy currents that leads to the generation of a thrust force and can result in movement over a metallic surface. This can benefit the inspection of metallic surfaces based on the driving platform provided by the induction planar actuator. Equations of the magnetic and electric fields are presented and, by means of these equations, the forces involved were calculated. The behaviour of thrust and normal forces was analysed through the equations and by numerical models, and compared with the results obtained by measurements on a device prototype built in the laboratory as part of the study. With relation to the surface under inspection that forms the secondary, three cases were analysed: (1) a double-layered secondary formed by aluminium and ferromagnetic slabs; (2) a single aluminium layer and (3) a single ferromagnetic layer. Theoretical and measured values of thrust and normal forces showed good correlation.

Estudo de um motor CC brushless aplicado no acionamento de um carro elétrico de pequeno porte

This work presents the study of an electric motor, which was used to drive a small electric car. The aim was to select a motor with characteristics of suited operation to drive the electric car at a speed range from 12 to 20 km/h. Tests were carried out on the electric car with the purpose of determining its dynamic behavior. The test results allowed to select a DC (Direct Current) brushless electric motor of 12 V and 5.9 A with 77% of maximum efficiency. A theoretical study was developed to determine the best relation of the movement transmission from the motor to the car. By doing that, it was possible to determine the characteristics of the operation of the motor in which it developed its maximum efficiency, when the electric car was started up. The speed ratio value resulted in 64:1. The study showed that to operate a 20 km/h speed, the car requires a mechanical power of 58 W from its electric motor.