| 摘要 |
An aircraft instrumentation system includes a plurality of air-driven instruments and a primary air pump for operatively driving the instruments. An air pressure regulator, coupled to the primary pump, selectively exhausts compressed air discharged by the primary pump so as to maintain a constant desired pressure at the instruments, and a backup pump is provided for operating the instruments in the event the primary pump fails. To avoid excessive cooling of the backup pump when the backup pump is not being operated and the aircraft is at altitude, a shroud is mounted so as to form an air space around the backup pump. Warm air, heated through compression by the primary pump and exhausted through the pressure regulator, is collected by a housing surrounding the pressure regulator and is conveyed, through a conduit, to the air space to warm the backup pump when the primary pump is operating.
|
