CO-AXIAL HELICOPTER CONTROL SYSTEM Russian patent published in 1995 - IPC

FIELD: aeronautical engineering. SUBSTANCE: co-axial helicopter control system consists of collective pitch control system and directional control system. Collective pitch control system consists of collective pitch control lever 1 and articulated rods and cranks 2, 3 and 4 of linkage running to spool valve of collective pitch hydraulic actuator 5. From actuating rod of hydraulic actuator 5, linkage articulated in succession by means of cranks and rods 6 and 7 runs to collective-pitch and differential-pitch mechanism 9 which is connected with wobble plates 14 and 15 on column 16. Control from wobble plates runs through rods and cranks to blades 17 and 18. Directional control system of co-axial helicopter consists of pedals 19 and articulated rods and cranks 20, 21, 22, 23 and 24 of the linkage running to spool valve of hydraulic actuator 25. Then linkage from actuating rod of directional control hydraulic actuator 25 articulated in succession by means of rods and cranks 26,27, 28 and 29 runs to collective-pitch and differential-pitch mechanism. Connected to actuating crank 26 through system of ropes, cranks and rods 30, 31, 32, 33 and 34 is turn control surface 35. Profiled stop 36 is rigidly secured to actuating crank of collective-pitch hydraulic actuator 5. Lever 37 engageable with stop 36 is rigidly secured to crank 25 of linkage running from pedals to spool valve of directional control hydraulic actuator 25. EFFECT: improved service characteristics due to limitation of closing of blades of main rotors. 4 dwg