Air cylinders are pneumatic linear actuators that are driven by a pressure differential in the cylinder's chambers. They may be single-acting (with a spring return) or double-acting.
Gearboxes and gearheads are speed reducers that consist of a set of gears, shafts, and bearings in an enclosed housing. In converting inputs to outputs, they reduce RPM and increase torque.
Hydraulic valves contain and transfer the flow and pressure of hydraulic fluid in hydraulic power systems. They range from simple shutoff valves to precision control valves.
V-belts and V-ribbed belts are power transmission drive belts with a triangular or trapezoidal cross section. They are available in a variety of belt materials, reinforcement styles, and speed configurations.