On an active method for improving the adaptability of fire truck transmissions to winter operating conditions

This work is a continuation of the study set forth in the article "Passive method of increasing the adaptability of fire engine transmissions to winter operating conditions. In-deed, the thermal regime has a direct impact on the performance of power transmissions of fire engines (FE). Therefore, the present work proposes and experimentally investigated for efficiency a technical solution providing an increase in traction-speed qualities, durability, economy of fire vehicles in low-temperature conditions. The transmission oil of the drive bridge was heated by an electric heater (EH) from two autonomous batteries connected in series with a resulting voltage of 24 V. The homemade EH with a nominal power of 115 W was mounted in the plug of the drain hole of the crankcase of the front driving controlled bridge of the fire tanker WT-5,0-40 (URAL-3255). On the fire truck, oil temperature measuring equipment was installed, including a temperature sensor TS 014-50M.B3.20/3 and showing a device TPM501 located in the driver's cab. During the study, the main phases of carrying out the FE service in the calculation were modeled. As it is, it follows a typical route (transport mode of operation) at ambient temperature -20 °C, in parking lots as at the place of call (fire), as well as after the FE returns to the unit garage, i.e. when serving in standby mode in conditions of natural convection in calm air at a temperature of 15 °C. It was found that electric heating is very effective. The use reduces by one minute the time to overcome the FE route with a length of 3,6 km. EH significantly accelerates the process of heating oil in the leading bridge in the calm air of the depot, to a lesser extent when following special mobile equipment and very slightly when parking at the place of call.