  We consider a new type of cooling mechanism for a suspended nanowire acting
as a weak link between two superconductive electrodes. By applying a bias
voltage over the system, we show that the system can be viewed as a
refrigerator for the nanomechanical vibrations, where energy is continuously
transferred from the vibrational degrees of freedom to the extended
quasiparticle states in the leads through the periodic modulation of the
inter-Andreev level separation. The necessary coupling between the electronic
and mechanical degrees of freedom responsible for this energy-transfer can be
achieved both with an external magnetic or electrical field, and is shown to
lead to an effective cooling of the vibrating nanowire. Using realistic
parameters for a suspended nanowire in the form of a metallic carbon nanotube
we analyze the evolution of the density matrix and demonstrate the possibility
to cool the system down to a stationary vibron population of $\sim 0.1$.
Furthermore, it is shown that the stationary occupancy of the vibrational modes
of the nanowire can be directly probed from the DC current responsible for
carrying away the absorbed energy from the vibrating nanowire.
