pspice laplace
I have applied dc motor simulation models - however, not with PSpice but with an block oriented simulation package for control system analysis.
However, are you sure that the PSpice model can fulfill your requirements.
There are many types as wel as small and large motors on the market. Can you adapt the properties of your motor to the Spice language ?
I propose to use instead the transfer function of the motor which, in principle, can be specified with the PSpice LAPLACE box. However, it is not a simple task to translate electro-mechanical properties of the motor to a corresponding transfer function.
Added after 20 minutes:
As an attachement you find a paper which describes translation between mechanical and electrical model parameters for a dc motor. Perhaps it helps.