Crosshead
In
Overview
On smaller engines, the connecting rod links the piston and the crankshaft directly, but this transmits sideways forces to the piston, since the crankpin (and thus the direction the force is applied) moves from side to side with the rotary motion of the crank. These transverse forces are tolerable in a smaller engine. A larger engine's much greater forces would cause an intolerable degree of wear on the piston and cylinder, as well as increasing overall friction in the engine.
A
Internal combustion engines
Internal combustion engines using crossheads make for easier maintenance of the top end of the engine, since the pistons can be easily removed. The piston rod is mounted on the underside of the piston and connected to the crosshead by a single nut in double acting engines. The large two-stroke
Steam engines
In the case of the steam engine, a crosshead is essential if the engine is to be double acting - steam is applied to both sides of the piston, which requires a seal around the piston rod. An exception is the oscillating cylinder steam engine which can be double acting and yet has no crosshead.
Locomotives
Crossheads in a steam locomotive can be mounted either to one guide mounted above the crosshead or to two, one above and one below (called an alligator crosshead since it has two "jaws"). The former was preferred in many more modern locomotives.
Marine engines
In many 19th century
See also
- Crosshead piston
- [1] in which the lateral force of the piston is eliminated
References
- ^ "The Two Stroke Crosshead Diesel Engine Crosshead Pin and Slippers". Marinediesels.info. Archived from the original on 2018-10-14. Retrieved 2013-07-22.
- ^ "3.2.2. Piston (reciprocating) compressor". Drucklufttechnik.de. Retrieved 2013-07-22.
