MAIN GEARBOXES VR-14/24

The main gearboxes VR-14 and VR-24 are designed for installation on helicopters Mi-14, Mi-8MT/17, Mi-8АMT/171, Mi-8MTV/172, Mi-24/25/35 and their modifications.

Its purpose is to transmit the power from two engines, i.e. TV3-117M/MT/VM (VR-14), TV3-117V/VMA (VR-24), VK-2500 (VR-14 and VR-24), to the main rotor, helicopter sets and to the antitorque rotor via the tail transmission with the corresponding to the rotation speed change as well as aerodynamic forces from the main rotor and the gearbox casing to the helicopter fuselage. The main gearboxes circuit is fixed-ratio, planetary.










MAIN TECHNICAL SPECIFICATIONS

VR-14 VR-24
Gear ratio:
  • to main rotor shaft
  • to tail rotor shaft
0,0128
0,1729
0,016
0,2158
Inlet shaft rotation speed, nominal, RPM 15000 15000
Power being transferred by main gearboxes:
  • maximum from each engine, h.p.
  • in the take-off mode, h.p.
  • in the nominal mode, h.p.
2100
2х1900
2х1700
2360
2х2200
2х1700
Mass, kg 842,5 830
Overall dimensions, mm:
  • length
  • width
  • height
1200
880
1760
1210
885
1765
Developer: Klimov Сorporation

KRASNY OCTIABR (since 1976) and Reductor-PM OJSC (since 1986) perform full-scale production of the VR-14 main gearbox. The production of VR-14 in KRASNY OCTIABR totaled near 2000 units.

KRASNY OCTIABR develops the repair documentation for the VR-14 and VR-24 main gearboxes, performs all types of repair, including overhaul and local field repair.

Service lifetime and calendar service life of main gearboxes VR-14

Gearbox layout Manufacture date Service lifetime (SLT) and calendar service life (CSL) Permitted service life for on-condition maintenance (OCM), hours Calendar service lives established for OCM*4,years
Till the first overhaul Assigned Between overhauls Till the first overhaul Between overhauls
SLT, hours CSL, years SLT, hours CSL, years SLT, hours CSL, years
7871.2800 since 1976 till 01.04.1979 1000 (750 for Мi-14) 10 2000 * 500 8 2000*1 - Till the first overhaul - 21
Between overhauls - 21
7870.0100 since 01.04.1979 till 01.05.1983 1000 10 8000*6 * 1000(2000*3) 8(10*3) 2000*1 1500*2 2000*3
7870.0200 since 01.05.1983 till 01.07.2000 1000 10 8000*6 * 1000(2000*3) 8(10*3) 2000*1 1500*2 2000*3
7870.0200 since 01.07.2000 till 01.01.2005 2000 10 8000*6 * 1000(2000*3) 8(10*3) 3500*5 1500*2 2000*3
7870.0200 since 01.01.2005 2000 10 8000*6 * 2000*3 10*3 3500*5 -

* Assigned calendar service life is defined by service life until the first overhaul and between overhauls.
*1 Bulletins Nos. 200-7-0-0290-4 (6.180.15-БЭ) и 208.6.0.0105.4 (6.140.14-БЭ).
*2 Bulletin No.200-5-0-0419-04 (К7870-02 БЭ-В).
*3 Bulletin No.200-6-0-0423-04 (6.180.43 БЭ-В, БЭ-Г).
*4 Bulletin No.200.9.0.0455.04 (К7870-10 БЭ-В).
*5 Bulletins Nos. 200.9.0.0440.04 (К7870-08 БЭ-В), K7870-08 БЭ-Г.
*6 Bulletins Nos. 200.3.0.0506.04 (К7870-16 БЭ-В), К7870-16 БЭ-Г, К7870-16 БЭ-АБ.