Abstract: A method includes providing a tapered roller bearing including an outer ring having a raceway surface, an inner ring having a raceway surface and a plurality of tapered rollers each having a rolling surface and a large end-face; optimizing a surface roughness of at least one surface selected from the following set of surfaces: the outer ring raceway surface, the inner ring raceway surface, the rolling surfaces of the tapered rollers and the large end faces of the tapered rollers; and black oxidizing the at least one first surface.

Abstract: The present disclosure relates to a method for demodulating a frequency modulated signal of a PMA standard wireless charging device, including: (1) reading coil signals, sampling the coil signals, and counting cycles; (2) extracting a frequency change according to a change in a cycle count; (3) determining data according to the frequency change and a frequency duration and outputting the data; and (4) splicing the outputted data. With the method, a demodulation part does not require a complex analog circuit, and the highest frequency desired at a digital circuit part is only 4 MHz. Moreover, at this frequency, there is only a simple addition operation, and the main operating frequency is below 236 KHz.