inflatable pressure has a great influence on the maximum oil filling capacity and oil
supply volume of the accumulator. In the process of analysis and design of closed
hydraulic system for aircraft, the thermal expansion or shrinkage of hydraulic oil at
the limit temperature should also be taken into account. The adjusting capacity of
the air chamber of hydraulic accumulator and booster tank should be checked
according to the actual working conditions, and the volume change caused by
thermal expansion of hydraulic oil should be absorbed or supplemented.
8.3.6 Conclusions
The hydraulic control system of aircraft often undergoes large temperature range
and storage process. In order to ensure the normal and reliable operation of the
hydraulic accumulator and booster tank and meet the functional requirements of the
hydraulic system in the range of storage temperature changes at extreme low
temperature and extreme high temperature, it is necessary to reasonably manage the
inflation of the air chamber of the hydraulic accumulator and the cylinder used in
the booster tank. When the air chamber of the aircraft hydraulic system is inflated,
the inflatable pressure management and the design of the hydraulic accumulator can
be carried out according to the following methods. The conclusion can also be
applied to the analysis of accumulator characteristics of ground hydraulic control
system with a large variation of ambient temperature.
(1) According to the requirement of working pressure and actual ambient temperature of the closed hydraulic system of aircraft, the charging mass of the gas
in air chamber of the hydraulic accumulator or cylinder of the booster tank can
be determined by Eq. (8.53).
(2) The inflatable pressure and its variation law under different ambient temperatures are determined by Eq. (8.54).
(3) The main performance of hydraulic accumulator, i.e., the working oil supply
and the maximum oil filling, is calculated by Eqs. (8.57) and (8.58).
Bibliography
1. Yin Y, Qu Y, Yan J (1991) An investigation on hydraulic servo systems with asymmetric
cylinder. In: Proceedings of the 1st international symposium on fluid power transmission and
control (ISFP91). Beijing Institute of Technology Press, Beijing, China, pp 271–273
2. Yin Y (1994) Study on velocity gain characteristics of hydraulic control system. Autopilot
Infrared Technol 73:23–29
3. Yin Y (1991) Research on flow matching control and precision of asymmetric hydraulic
cylinder servo system. Master’s thesis of Shanghai Jiao Tong University
4. Yin Y (1993) The financial pressure characteristics of symmetric and unequal positive
openings were studied. Hydraul Pneum Seals 50:22–26
48
8 Pneumatic Actuators, Driving Elements and Accessories
supply volume of the accumulator. In the process of analysis and design of closed
hydraulic system for aircraft, the thermal expansion or shrinkage of hydraulic oil at
the limit temperature should also be taken into account. The adjusting capacity of
the air chamber of hydraulic accumulator and booster tank should be checked
according to the actual working conditions, and the volume change caused by
thermal expansion of hydraulic oil should be absorbed or supplemented.
8.3.6 Conclusions
The hydraulic control system of aircraft often undergoes large temperature range
and storage process. In order to ensure the normal and reliable operation of the
hydraulic accumulator and booster tank and meet the functional requirements of the
hydraulic system in the range of storage temperature changes at extreme low
temperature and extreme high temperature, it is necessary to reasonably manage the
inflation of the air chamber of the hydraulic accumulator and the cylinder used in
the booster tank. When the air chamber of the aircraft hydraulic system is inflated,
the inflatable pressure management and the design of the hydraulic accumulator can
be carried out according to the following methods. The conclusion can also be
applied to the analysis of accumulator characteristics of ground hydraulic control
system with a large variation of ambient temperature.
(1) According to the requirement of working pressure and actual ambient temperature of the closed hydraulic system of aircraft, the charging mass of the gas
in air chamber of the hydraulic accumulator or cylinder of the booster tank can
be determined by Eq. (8.53).
(2) The inflatable pressure and its variation law under different ambient temperatures are determined by Eq. (8.54).
(3) The main performance of hydraulic accumulator, i.e., the working oil supply
and the maximum oil filling, is calculated by Eqs. (8.57) and (8.58).
Bibliography
1. Yin Y, Qu Y, Yan J (1991) An investigation on hydraulic servo systems with asymmetric
cylinder. In: Proceedings of the 1st international symposium on fluid power transmission and
control (ISFP91). Beijing Institute of Technology Press, Beijing, China, pp 271–273
2. Yin Y (1994) Study on velocity gain characteristics of hydraulic control system. Autopilot
Infrared Technol 73:23–29
3. Yin Y (1991) Research on flow matching control and precision of asymmetric hydraulic
cylinder servo system. Master’s thesis of Shanghai Jiao Tong University
4. Yin Y (1993) The financial pressure characteristics of symmetric and unequal positive
openings were studied. Hydraul Pneum Seals 50:22–26
48
8 Pneumatic Actuators, Driving Elements and Accessories