Ratcheting is a novel phenomenon for coupled oscillator systems that gives rise to asymmetric desynchronization and frequency locking of oscillators. A particular type of robust heteroclinic network — heteroclinic ratchet — induces the ratcheting effect. In this talk, this effect will be explained with an example of 4-cell oscillator system and some other examples that have the same effect will be shown. Finally, the definition of heteroclinic ratchet will be given for more general dynamical systems on N-dimensional torus and the relation between heteroclinic ratchets and different synchronization types of oscillators will be discussed.