Studying the Temperature Characteristics of Oil at the Outlet From the K27-145 Turbocharger Rotor Bearing

Abstract

Turbocharging is a promising solution for increasing the specific power of motor-and-tractor equipment, which allows increasing power up to 50%. At the same time, a significant growth of speed, load, and temperature modes leads to a significant increase in the number of failures and a decrease in reliability by 2–3 times. Theoretical and experimental studies established that the temperature of the bearing and oil at the turbocharger drain changes under the influence of the inlet oil temperature to the TCR bearing, the TCR rotor shaft speed, and the change in the oil pressure at the input to the TCR bearing. This allows setting the limits of the TCR bearing performance in extreme operating conditions. The installation of an autonomous TCR lubricating and braking device maintains the required reliability level and increases failure-free operation. The hydraulic accumulator installed in the lubrication system of the engine turbocharger regulars lubricates and cools the rotor bearings when the ICE crankshaft speed drops. The incorporation of a braking device reduces the rundown time of the rotor and thereby prevents oil starvation and dry friction of the rotor bearing. The combined use of the hydraulic accumulator and the braking device minimizes the risk of dry friction and accidental failure of the turbocharger. We proved that the braking device of the TCR rotor built into the intake system of an ICE with the calculated design parameters reduces the rotor rundown time by 30–35%. This reduces the dimensions and operating time of the hydraulic accumulator and simultaneously eliminates surges in the compressor section of the TCR and any breakage of its parts. In these conditions, it is relevant to develop independent systems to lubricate the TCR bearings and replenish them using built-in hydraulic accumulators during start-up, significant loads at minimum crankshaft speeds, and engine stalling.

Keywords

• turbocharging
• bearing
• turbocharger
• engine oil
• lubrication system