A Cable-Free Ironless Linear Motor with Power Provisioning Capability to the Payload

Cables typically connect to the movers of linear motors for power and communication, which can lead to additional drag, friction, vibration, maintenance, and limited working distances. By integrating wireless power transfer and linear motors, the latter can eliminate the need for cables or energy chains, thereby enhancing performance, allowing unlimited working distance, and reducing mover mass. The mutual inductance of transmitting and receiving windings plays a vital role in wireless power transfer systems. To maintain stable motion and electrical operation, the mutual inductance should not fluctuate excessively along the rail. Mathematical derivations for numerical evaluations have been derived to calculate the self and mutual inductances of rail transmitter and mover receiver rectangular windings and to model power performances. A prototype motor has been constructed to confirm the feasibility of this combination.

I. Introduction

Linear motors are extensively used in various industries, transportation, and electronic direct drive applications. Compared to their rotary counterparts, linear motors avoid mechanical conversion from rotary motion to linear motion, resulting in higher velocity, acceleration, and positioning accuracy, enhanced efficiency, superior thrust density, and reduced maintenance [1] – [4]. However, to power the force windings and sensors, and to communicate with the on-stator controller, movers are typically connected to stators by cables. These cables can cause security and reliability issues, additional drag and friction, vibration, maintenance, and limited working distance.