435F

Hydraulic pressure generation by the 435F pump

The 435F creates working pressure in the hydraulic line by converting mechanical rotation of the drive shaft into hydraulic fluid flow. The nominal outlet pressure at zero delivery is 150 ±7.5 kgf/cm². The nominal flow rate is not less than 28 L/min within the pressure range from 0 to 142.5 kgf/cm². These values make the pump suitable for hydraulic systems where pressure must remain stable while supplying flight-control or servicing consumers.

Mechanical drive of the 435F pump

The 435F is a mechanically driven hydraulic pump. The drive shaft operates at a nominal speed of 2070 rpm. According to the supplied data, shaft rotation is left-hand, or counterclockwise when viewed from the drive end. This parameter is important during replacement or installation because pumps with the wrong rotation direction may not deliver pressure correctly and can be damaged. The drive interface, shaft, mounting points and sealing surfaces must be checked before installation.

435F on An-22 hydraulic systems

The 435F is used on the An-22 Antei heavy military transport aircraft. On this aircraft, 435F pumps are part of the booster hydraulic system for flight control. The system is divided into left and right independent circuits. According to the supplied data, the left system is powered by two 435F pumps installed on accessory gearboxes of the 1st and 3rd NK-12MA engines, while the right system is powered by pumps installed on the 2nd and 4th engines.

435F with BU-170TD flight-control boosters

In the An-22 hydraulic system, the 435F supplies pressure to BU-170TD hydraulic boosters. These boosters actuate the rudder, elevators and ailerons of the aircraft. Since the An-22 is a heavy aircraft with large control surfaces, the hydraulic pump must provide stable pressure for reliable booster operation. Any pressure drop, leakage or flow instability can affect the performance of the flight-control hydraulic system, so pump condition and filtration are important during maintenance.

Associated hydraulic units for 435F

The 435F works as part of a complete hydraulic system. It may operate together with NS-39 electric pumping stations, AD-50-type pressure automatics, hydraulic accumulators, high-pressure filter elements and AMG-10 hydraulic fluid circuits. Electric pumping stations can serve as autonomous or reserve pressure sources, while pressure automatics help regulate idle cycles and maintain the required pressure range. The pump should therefore be checked not only separately, but also within the hydraulic circuit where it is installed.

Use of 435F in ground hydraulic equipment

Besides aircraft installation, the 435F is used in ground hydraulic units and test stands for servicing aircraft and helicopter hydraulic systems. It may be applied in UPG-type checking equipment for Mi-8, Mi-17 and Mi-26 hydraulic systems, depending on the stand configuration. In ground use, the pump is valued for its pressure capability and stable output. Before adaptation to a test stand, working fluid, drive speed, rotation direction, filtration and pressure protection must be verified.

Supply and documentation for 435F

For supply, the pump should be requested by its full designation: 435F / 435Ф. If a related modification is required, such as 435FT or 435MF, this must be stated clearly. For aircraft use, passport, storage records, repair history and test results are important. Before installation, the pump should be checked for pressure, flow rate, leakage, shaft rotation direction, drive interface, fittings, housing condition and compatibility with the aircraft or test stand hydraulic system.