A transport model of elastically coupled particles in a two-dimensional potential is investigated. Here, we propose that one dimension of the model is exerted by an AC drive and an external noise, and the other dimension by neither AC drive nor external noise. The effects of system and external parameters on the directed current under an overdamped case are discussed. The studies show that particles can transfer energy from one direction to its perpendicular direction through coupling, thereby producing a directed current. There is an optimal value of the spring free length or the coupling intensity at which the directed current can reach a maximum. For a fixed coupling intensity or noise intensity, the directed current will oscillate as the free length of spring varies, that is, multiple peaks appear. Moreover, a stochastic resonance appears in the directed current as noise intensity varies. Finally, when the degree of asymmetry of the ratchet potential achieves a maximum value, the current reversion takes place.