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Hackworth valve gear

From Wikipedia, the free encyclopedia

Hackworth valve gear on steam locomotive 'Lydia' at the Perrygrove Railway.
Hackworth valve gear on Apedale Valley Light Railway locomotive 'Stanhope'
Hackworth valve gear on Tal-y-Llyn Railway locomotive 'Edward Thomas'

The Hackworth valve gear is a design of valve gear used to regulate the flow of steam to the pistons in steam engines. It is a radial gear, with an actuating lever driven from the crank. The drive may be taken directly from the crank or indirectly via a return crank (as in all pictures). The other end of the actuating lever is attached to a die block which slides in a slotted link. When the link is vertical, the engine is in mid-gear. Forward, reverse and cut-off adjustments are made by moving the link away from the vertical. The valve rod is pivoted to a point on the actuating lever.[1]

History

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The gear was patented by John Wesley Hackworth (1820-1891), son of Timothy Hackworth, in 1859.[2]

Klug's valve gear

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Hackworth valve gear was a precursor to Klug's valve gear, but it differs from the latter in that the eccentric rod's suspension point moves to-and-fro in a straight line by means of a die block sliding in a slotted guide.[3]

See also

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References

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  1. ^ "What is HACKWORTH VALVE GEAR?". Retrieved 15 February 2014.
  2. ^ "Timothy Hackworth". John Wesley Hackworth.
  3. ^ Josefsson, Lars. "Lars Josefsson. Important marine boilers information". Retrieved 15 February 2014.