Linear gate motors are also called Worm Drives or Hydraulic Actuators.
How they Work - Linear Swing Gate Motors
Linear Gate Motors have an electric motor with gearing and an acme screw (worm drive) or have an electric motor, hydraulic pump and actuator and is fitted to the gate and gate post. They have control electronics in a separate weather proof box. When activated by wireless hand held remote control (handset) or other device like a digital keypad or intercom the motors length reduces (retracts) pulling the gate open and increases (extends) to push the gate closed.
Linear motors have various different methods for setting the open and close limit of the gate. Some rely on a hard stop for the gate in the open and closed position while others rely on a hard stop for close only and have an encoder (rotation counter) to determine the open position. Others have built in hard stops and some have limit switches.
Double Swing Gates require a two motors, one for each gate panel, but only one control box, which controls both motors keeping them synchronised requiring a cable across the driveway. Normally only a two core cable is required if the motor relies on hard stops but require extra cable for an encoder or limit switches so it's a good idea to include at least a five core cable or a heavy duty two core cable and a lighter duty 4 core cable just in case.