By Martyn Herman RIO DE JANEIRO, Aug 10 (Reuters) - Russia's Olga Zabelinskaya protested her innocence after winning the silver medal in the women's time trial on Wednesday, a week after almost flying home because a previous doping ban looked like ruling her out of the Olympics. The 36-year-old Russian mother-of-three was beaten to the top step of the podium by American veteran Kristin Armstrong, missing out on victory by 5 seconds after a strong ride around the 29.7 km course. More...