By Sameer Manekar Aug 27 (Reuters) - Australian shares closed unchanged on Friday, dragged by retail conglomerate Wesfarmers and rare earths miner Lynas, while investors awaited Federal Reserve Chair Jerome Powell's speech for clues on the central bank's tapering timeline. Wesfarmers WES.AX dropped 2.8% after it flagged a gloomy start to fiscal 2022, even as it announced a surprise A$2.3 billion ($1.66 billion) buyback. Overnight, Wall Street indexes declined as positive economic data and hot inflation has prompted talks of the Fed potentially beginning tapering asset purchases and its accommodative stance.