How does retractable gear work of single engine airplane?

Question

How does retractable gear work of single engine airplane?

Answer 1

It works the same way as in multi-engine aircraft. Retraction and extension can be either electrically or hydraulically actuated. When the (electric) gear select lever is raised up, it sends an electric current to the retract motor in the wheel bay, which in turn, (by a suitable mechanical system), raises up the gear. To lower the gear the electric motor turns the other way. In the hydraulic system, a hydraulic pump sends the fluid under pressure to the actuator on the gear. When gear is selected 'up' the actuator retracts the gear and, vice versa, while lowering the gear, the fluid is supplied from the other end of the actuator which moves the gear down. In both systems the gears while retracted up are securely locked and in the extended position are similarly locked.

Answer 2

A basic system found on Piper aircraft utilizes an electrically powered hydraulic pump.  Basically, it pumps hydraulic fluid from a reservoir into "up" or "down" lines which lead to each individual landing gear.  On Arrows and Seminoles, for example, 1800 psi of hydraulic pressure is put into the "up" lines which retracts the gear into the belly of the aircraft.  When that happens, circuits are closed that indicate to the pilot that the gear is retracted.  Similarly, 800 psi of pressure is applied to the "down" lines to lower the gear.  Gravity and springs help the gear to fall as well, hence the reason for less PSI required.  Pretty simple really...just hydraulic fluid and piston assemblies that mobilize the landing gear.  System is actuated by the pilot with the gear selector switch in the cockpit.

Answer 3

There are many different designs and arrangements for retractable landing gear.  Most retractable-gear light aircraft have either electric or hydraulic landing gear, though there have been a few with manually operated gear, of which the best known are Mooneys.

It's really to extensive a subject to cover properly here, but you can find large amounts of information, including photographs and diagrams, on the internet.  Try an Internet search on "retractable landing gear" or on any particular type of airplane you are interested in.