In the absence of external force and noise, a deterministic transport model for asymmetrically coupled nonlinear oscillators in a ratchet potential is established. By numerical simulation, both directed current and reversely directed current can be obtained by selecting appropriate parameters. The complex dependences of current velocity on the model parameters are discussed. It is observed that the average velocity of the particle chain varies non-monotonically with coupling strength and potential height, indicating a generalized resonance phenomenon. When the other parameters are fixed, the speed curve which is dependent on spring free length has a roughly inverse symmetry, and there also exists a generalized multi-peak resonance.