Dharmacakra

"The Dharmacakra symbol is represented as a chariot wheel (Sanskrit cakram) with eight or more spokes. It is one of the oldest known Buddhist symbols found in Indian art, appearing with the first surviving post-Harappan Indian iconography in the time of the Buddhist king Aśoka. The Dharmacakra has been used by all Buddhist nations as a symbol ever since. In its simplest form, the Dharmacakra is recognized globally as a symbol for Buddhism." According Wiki http://en.wikipedia.org/wiki/Dharmacakra