chain pump

from the GNU version of the Collaborative International Dictionary of English.

• A pump consisting of an endless chain, running over a drum or wheel by which it is moved, and dipping below the water to be raised. The chain has at intervals disks or lifts which fit the tube through which the ascending part passes and carry the water to the point of discharge.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A water pump consisting of a series of buckets on a chain, wheel or drum