EPK-2T-90

Windshield cleaning function of EPK-2T-90

The EPK-2T-90 converts 27 V DC electrical power into oscillating movement of the windshield wiper brush. The mechanism moves the output shaft through a limited angular sector, and the attached arm transfers this movement to the wiper blade. This allows the brush to clean the pilot’s forward glazing and maintain visibility in precipitation or wet contamination. The drive must operate evenly, without jamming, irregular movement or excessive play. Brush pressure, arm length, sweep angle and electrical supply condition all affect the quality of windshield cleaning.

EPK-2T-90 construction with D-70T motor

The EPK-2T-90 includes a D-70T DC electric motor, a two-stage planetary reduction gear and a crank-rocker mechanism. The motor produces rotation, while the reduction gear lowers speed and increases torque. The crank-rocker mechanism then converts continuous shaft rotation into reciprocating movement of the wiper brush. This arrangement allows the mechanism to provide stable sweep movement within the required angular range. The unit is installed close to the cockpit windshield, so the drive housing, shaft seal, mounting points and external wiper linkage should be checked during maintenance.

Automatic return and reset mode of EPK-2T-90

The EPK-2T-90 has a built-in interrupter for automatic return and stopping of the brush in the end parked position. When the system is switched to reset mode, the mechanism returns the wiper to its initial position outside the main crew field of view. The stop is performed through the dynamic braking circuit, which helps fix the brush in the required end position. This function is important because a wiper blade left in the central viewing area can interfere with visibility. Correct reset operation should be checked together with motor performance and switch circuits.

Installation of EPK-2T-90 on Mi-8 / Mi-17 helicopters

On Mi-8 / Mi-17 / Mi-171 helicopters, EPK-2T-90 mechanisms are installed in the pilots’ cockpit, normally above the forward heated windshields on the cockpit canopy frame. The mechanism body is mounted inside the cockpit, while the output shaft passes through the structure to the outside, where the drive arm and wiper brush are attached. The system is usually installed in pairs: one mechanism for the left windshield of the captain and one for the right windshield of the second pilot. Control switches are placed on the cockpit electrical panels.

Identification and ordering of EPK-2T-90

Before ordering EPK-2T-90, the aircraft type, installation side, required condition and documentation set should be confirmed. The mechanism may be required for operational replacement, repair stock or overhaul support of the windshield cleaning system. It is also useful to confirm the arm length, sweep angle, connector configuration, control switch wiring and whether interchangeability with other EPK-2T versions is required. For acceptance, the buyer should clarify passport availability, serviceability records, repair status and installation documentation.

Related system equipment: EPK-2T-60. These positions are grouped by system function and installation context, not as interchangeable replacements.