A quill drive is a mechanism that allows a drive shaft to shift its position (either axial

Axial

Axial may mean:* Along the same line as an axis of rotation in geometry* A type of modal frame in music* One of several anatomical directions in an animal body* Axial age, the period from 800 to 200 BC in China, India and the western world...

ly, radially, or both) relative to its driving shaft. It consists of a hollow driving shaft (the quill

Quill

A quill pen is a writing implement made from a flight feather of a large bird. Quills were used for writing with ink before the invention of the dip pen, metal-nibbed pens, the fountain pen, and, eventually, the ballpoint pen...

) with a driven shaft inside it. The two are connected in some fashion which permits the required motion.

One example of a quill drive is found in a drill press where the quill allows the chuck

Chuck (engineering)

A chuck is a specialized type of clamp used to hold an object, usually an object with radial symmetry, especially a cylindrical object. It is most commonly used to hold a rotating tool or a rotating workpiece...

 to move up and down while still being driven.

Quill drives have been extensively used in railroad electric locomotive

Electric locomotive

An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or an on-board energy storage device...

s to connect between the traction motor

Traction motor

Traction motor refers to an electric motor providing the primary rotational torque of a machine, usually for conversion into linear motion ....

s and the driven wheels. The two are linked by a flexible drive which allows a degree of radial motion and possibly a small amount of axial motion. This smooths the drive from the motors and isolates them from mechanical shock as well. Quill drives were used by many electric locomotives in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, particularly those of the Pennsylvania Railroad

Pennsylvania Railroad

The Pennsylvania Railroad was an American Class I railroad, founded in 1846. Commonly referred to as the "Pennsy", the PRR was headquartered in Philadelphia, Pennsylvania....

—their long-lasting GG1

PRR GG1

The PRR GG1 is a class of electric locomotives that was built for the Pennsylvania Railroad for use in the northeastern United States. A total of 140 GG1s were constructed by its designer General Electric and the Pennsylvania's Altoona Works from 1934 to 1943....

 design being perhaps the best known. Many locomotives built in France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 and Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

 used quill drives as well, allowing higher locomotive speed. The English Electric

English Electric

English Electric was a British industrial manufacturer. Founded in 1918, it initially specialised in industrial electric motors and transformers...

 built NZR ED class

NZR ED class

The NZR ED class locomotive was a class of electric locomotive used in Wellington, New Zealand. They were built by English Electric and New Zealand Railways between 1938 and 1940, and hauled mainly passenger trains on the Wellington region's 1500 V DC electrification, and banked freight trains on...

used a quill drive, but was found to be hard on the track.