Embodiments of the present disclosure are directed to devices, systems and methods for increasing the accuracy of delivery of a fluid/drug in a fluid/drug delivery device/system. In some embodiments, a fluid infusion device is provided for delivering a drug into the body of a user, and includes at least one housing, a reservoir, a plunger and a drive-screw, where the drive-screw includes a first end and a second end, the first end being configured to operatively connect to the plunger. The device may further include a driving mechanism comprising at least a motor and one or more gears, where the one or more gears include a rotating sleeve configured for engagement with the second end of the drive-screw, a controller for at least controlling operation of the driving mechanism, and a support casing configured to substantially support the rotating sleeve and enable substantially free rotation of the rotating sleeve therein.
