But the static mechanical pumps could not chase after groundwater that continually changed course through the complex terrain. (discovermagazine.com)
Like many mechanical pumps, the heart has two functional parts. (pethealthnetwork.com)
Active solar: As an energy source, energy from the sun collected and stored using mechanical pumps or fans to circulate heat - laden fluids or air between solar collectors and a building. (eia.gov)