Joy Valve Gear - AbsoluteAstronomy.com

Joy valve gear is a type of locomotive

Locomotive

A locomotive is a railway vehicle that provides the motive power for a train. The word originates from the Latin loco – "from a place", ablative of locus, "place" + Medieval Latin motivus, "causing motion", and is a shortened form of the term locomotive engine, first used in the early 19th...

valve gear

Valve gear

The valve gear of a steam engine is the mechanism that operates the inlet and exhaust valves to admit steam into the cylinder and allow exhaust steam to escape, respectively, at the correct points in the cycle...

, patented in 1870, where the movement is derived from a vertical link connected to the connecting rod. The vertical movement is translated into the horizontal movement required by the valve spindle by a die block moving in a slide which can be varied in inclination. The necessary 90 degree phase shift is obtained not from an eccentric as with most designs but from the 90 degree phase difference between the horizontal and vertical components of the motion of the connecting rod.

Joy gear was also used by John Fowler & Co.

John Fowler & Co.

thumb|right|John Fowler & Co. [[steam roller]] of 1923John Fowler & Co Engineers of Leathley Road, Hunslet, Leeds, West Yorkshire, England produced traction engines and ploughing implements and equipment, as well as railway equipment. Fowler also produced the Track Marshall tractor which was a...

and several other steam traction engine

Traction engine

A traction engine is a self-propelled steam engine used to move heavy loads on roads, plough ground or to provide power at a chosen location. The name derives from the Latin tractus, meaning 'drawn', since the prime function of any traction engine is to draw a load behind it...

manufacturers.

Designed by David Joy (1825–1903) Locomotive and Marine engineer, Joy valve-gear was used extensively on L&YR and LNWR locomotives, and also by the Manning Wardle

Manning Wardle

Manning Wardle was a steam locomotive manufacturer based in Hunslet, Leeds, West Yorkshire, England.- Precursor companies :The city of Leeds was one of the earliest centres of locomotive building; Matthew Murray built the first commercially successful steam locomotive, Salamanca, in Holbeck, Leeds,...

-built narrow gauge 2-6-2

2-6-2

Under the Whyte notation for the classification of steam locomotives, 2-6-2 represents the wheel arrangement of two leading wheels, six coupled driving wheels and two trailing wheels.Other equivalent classifications are:...

locomotives of the Lynton & Barnstaple Railway

Lynton and Barnstaple Railway

The Lynton & Barnstaple Railway opened as an independent railway in May 1898. It was a single track narrow gauge railway slightly over long running through the rugged and picturesque area bordering Exmoor in North Devon, England. Although opened after the 1896 Light Railways Act came into force,...

.

The last locomotives with Joy valve gear to remain in service with British Railways were the LNWR G2 and G2A classes

LNWR G Class

The London and North Western Railway G Class along with modifications that made them into G1, G2 and G2a classes, is a class of 0-8-0 steam locomotives designed for heavy freight work. They are known to railway enthusiasts as "Super Ds". This is because a large number of G1 class engines were...

, one of which is preserved.

See also