RECENT DRDO DEVELOPMENTS

Transmission Controller for Indigenous Transmission System of MBT ArjunTransmission Controller

Combat Vehicles Research & Development Establishment (CVRDE), Avadi, has developed an Indigenous Transmission Controller for Indigenous Transmission System of MBT Arjun. This is a heavy duty, high power transmission-cum-steering system. This hard-wired semi-automatic transmission controller developed to control the above transmission, caters for manual mode of operation. In manual mode, gear- selection is left to the driver from 1st to 4th gear. The electronic control box receives control commands from the gear selection unit. After processing these commands, control logic signals are sent to actuate solenoid valve to shift gears or inhibit certain actions. Gear selector unit and transmission junction box have been developed and integrated in the indigenous transmission vehicle. Field trials compiling 1200 km have been successfully completed.

The main features of the transmission controller are:

  • Four forward and two reverse speed operation selection

  • Lock-up converter operation for smooth gear shift during change of gears by disengaging the converter solenoid for a minimum period of 600 ms

  • Lock-up solenoid operation by engaging first and third gear simultaneously

  • Direction lever-lock at engine speed exceeding safety limit and unlock mechanism to prevent accidental direction selection, and

  • Safety provision for engaging the gear-solenoid after sensing the control pressure using the pressure switches.

Mechanical Steering Unit for MBT Arjun

The Hydrostatic Steering Unit of MBT Arjun is a highly sophisticated component which is not available indigenously in higher power range for heavy vehicles like Arjun tank weighing over 58 tons. Therefore, a necessity was felt to develop a mechanical system to meet the steering requirement of MET Arjun as a fall back option for this imported critical component.The Combat Vehicles Research & Development Establishment (CVRDE) Avadi, has designed, developed and successfully lab tested the Mechanical Steering Unit. It is simple, light and efficient steering system meeting the battlefield requirements of all possible maneuvering. The transmission fitted with mechanical steering unit is likely to be installed in the test vehicle shortly for carrying out automotive trials.