Patent ID: 8145384

Claim:
A traveling speed reduction gear lubricating oil cooling device in a work vehicle, including: a tubular wheel mounting sleeve that rotates as one with wheels of said work vehicle; a traveling motor used to drive said wheel mounting sleeve; a reduction gear unit housed inside said wheel mounting sleeve and constituted with a gear mechanism that slows rotation of said traveling motor and transmits the slowed rotation to said wheel mounting sleeve; and a circulation path and a lubricating oil pump disposed outside said wheel mounting sleeve, via which reduction gear lubricating oil drawn out of said wheel mounting sleeve is cooled at an oil cooler and then made to travel back into said wheel mounting sleeve: characterized in that said traveling speed reduction gear lubricating oil cooling device comprises: a first temperature sensor that detects the temperature of said traveling motor; a second temperature sensor disposed in said circulation path outside said wheel mounting sleeve, which detects the temperature of the lubricating oil; a traveling motor reference temperature setting means for setting in advance a reference temperature for said traveling motor; a motor temperature comparison means for comparing the temperature detected by said first temperature sensor with said reference temperature set for said traveling motor; and a startup operation control means for increasing the rotation speed of a drive motor for the lubricating pump in correspondence to a rise in the temperature detected by said second temperature sensor within a speed range lower than a normal operating speed upon determining that the temperature detected by said first temperature sensor is equal to or higher than said reference temperature set for said traveling motor.