Here's a simple working solution:
@-moz-keyframes spin { 100% { -moz-transform: rotate(360deg); } }
@-webkit-keyframes spin { 100% { -webkit-transform: rotate(360deg); } }
@keyframes spin { 100% { -webkit-transform: rotate(360deg); transform:rotate(360deg); } }
.elem:hover {
-webkit-animation:spin 1.5s linear infinite;
-moz-animation:spin 1.5s linear infinite;
animation:spin 1.5s linear infinite;
}