623K

Hydraulic pressure generation by the 623K pump

The 623K is driven mechanically from the aircraft engine, gearbox or accessory drive system. As the drive shaft rotates, the pump draws hydraulic fluid from the hydraulic tank and sends it into the pressure line. The nominal working pressure is 150 kgf/cm², with maximum pressure up to 170 kgf/cm² for not more than one minute. This allows the pump to support high-load hydraulic consumers while remaining compact enough for installation in aircraft gearbox compartments.

Installation of 623K on aircraft gearboxes

The 623K is installed on gearbox drive flanges or accessory drive gearboxes, depending on aircraft configuration. On helicopters such as Mi-8 and Mi-17, this type of installation allows the pump to remain driven from the transmission system. This is important because hydraulic pressure can still be maintained when the main rotor system continues rotating in autorotation. During installation, the drive splines, mounting flange, rotation direction, sealing surfaces and hydraulic fittings must be checked carefully.

623K operation with pressure unloading units

In the hydraulic system, the 623K works together with pressure control and unloading devices. Units such as GA-77V-type pump unloading automatics can switch the pump flow to bypass / return mode when system pressure reaches the required level. This protects the pump and hydraulic fluid from unnecessary heating and reduces wear during periods when full pressure delivery is not needed. The pump also works with hydraulic accumulators, which smooth pressure pulsations and compensate for short peak demands.

Hydraulic circuit components connected with 623K

The 623K is part of a larger hydraulic circuit and does not operate alone. The pump receives AMG-10 fluid from the hydraulic tank, pushes it through fine filters and supplies pressure to hydraulic consumers. Check valves such as OK-10A prevent reverse flow when pump speed drops or the pump stops. Pressure sensors, manometer transmitters and pressure switches monitor system pressure and send information to cockpit indications or warning systems. Correct operation of these components is important for stable pump performance.

623K and helicopter hydraulic consumers

On helicopters such as Mi-8, Mi-17 and related configurations, the 623K may supply pressure to hydraulic boosters and actuators used in flight control and auxiliary mechanisms. Typical consumers include KAU-30B and RA-60B control boosters, hydraulic cylinders, friction-control mechanisms and other servo-driven equipment depending on the specific hydraulic system. Because flight control assistance depends on stable hydraulic pressure, pump condition, filtration and pressure regulation must be checked during maintenance.

Working fluid and operating conditions of 623K

The 623K operates with AMG-10 mineral hydraulic oil. The supplied data specify AMG-10 according to GOST 6794-53. Clean fluid and proper filtration are critical, because the pump works at high pressure and is sensitive to wear particles, contamination and poor suction conditions. Fine filters, such as 8D2-type or FG-11BN-type filters depending on system configuration, are typically installed in the pressure line after the pump to protect downstream hydraulic components.

Supply and related 623-series pumps

The 623K belongs to the 623-series aircraft hydraulic pump family. Related modifications include 623, 623ANM, 623KL, 623KP, 623T1 and 623Ya. These versions should not be treated as automatically interchangeable without checking rotation direction, fittings, mounting flange, pressure parameters and aircraft system documentation. For procurement, the full designation 623K / 623К, required condition and documentation should be confirmed before shipment.