Design and testing of a novel rotary transformer for rotary ultrasonic machining

Abstract

This paper presents the design and testing of a novel rotary transformer for rotary ultrasonic machining (RUM). The transformer structure is innovatively designed for easy assembly and disassembly, which provides increased convenience to tool replacement in RUM. Circuit analysis shows the efficiency loss caused by the structure simplification is less than 5%. Also, the effect of the primary core angle and air gap length on coupling coefficient is studied for guiding the design. A rotary transformer with 90°p rimary core and 1.0 mm air gap is achieved. Contrast tests were carried out in simulation and experiment. Results show this novel rotary transformer transmission efficiency is 0.8972, which is agree with the theoretical value.

Comparing different configurations for rotary transformer of wound-rotor resolvers

“…1. The studied configurations for RT: (a) RT1: Conventional RT, (b) RT2: Flat-plane, disk type RT [14], (c) RT3: L-form RT [16], (d) RT4: segmented primary core RT [18], (e) RT5: with toothed cores [19], and (f) RT6: equipped with sandwiched winding [20].…”

“…RT with wafer-form winding is developed in [17] for hybrid vehicle applications. In [18] a new configuration with segmented primary core is proposed for supplying circuit of an ultrasonic shaker. The proposed design of [18] has a high leakage inductance and low power loss.…”

“…In [18] a new configuration with segmented primary core is proposed for supplying circuit of an ultrasonic shaker. The proposed design of [18] has a high leakage inductance and low power loss. Another configuration based on toothed primary and secondary cores is proposed in [19].…”

Characteristic analysis and optimization of modified rotary transformer

“…In [2], a high-frequency current of 100kHz is employed to reduce the impact of leakage inductance on the full-bridge circuit. In [3], a dedicated rotary transformer is designed for a specific rotary machining device, achieving a transmission efficiency of 89.72%. The study delves into the relationship between the coupling coefficient and the air gap length, concluding that a smaller air gap results in a larger coupling coefficient.…”

Coreless inductive power supply for ultrasonic transducer on machine tool

“…The power transferring through a transformer is a better and more efficient way compared to the common way with contacts [5,6,7,8]. A transformer composed of magnetic cores and windings is the key component in inductive power transferring.…”