how do excavators and dozers keep the oil pickup screen buried in oil on steep slopes?
They have large, deep oil pans, use baffles and the pickup is very close to the pan bottom.
Good day See the broken lines in the pan. Most engines have a limit to which they can be tilted. Kind regards Uffex
Excavators and dozers usually have two oil sumps in the crankcase, one front and one rear, plus a scavenge pump piggy-backed onto the main oil pump. The main oil sump is generally towards the front, and is lower than the rear oil sump. The oil suction line pickups are mounted low in these oil sumps, with the main oil pump sucking from the front oil sump, and the scavenge pump sucking from the rear oil sump. When the machine is operating at a steep front-upwards angle, the scavenge pump is picking up oil running to the rear oil sump, and then returning it to the front oil sump. When the machine is operating at a steep rear-upwards angle, the front oil sump is quite well positioned to provide a continuous oil supply, and the scavenge pump can quite happily operate with only a very small amount of oil being picked up. Not all engines are set up this way, some of the smaller and lower-cost engines only have the main oil pump, but have a very deep and narrow oil sump in the crankcase, which provides adequate oil reserves on steep slopes, for all but the most extreme situations.
I just mounted a oil pump on a komatsu D155 Engine Friday and the pump has a piggybacked scavenge pump hooked up to it with a pipe and pickup to the rear of motor. It drops the oil in the front sump for the main pump to pick up and supply oil to the rest of engine. Simon C
I've seen a couple skid steers grenade engines from operators doing "cowboy" 2 wheel wheelies for too long.
I've changed an engine in an older New Holland skid steer from exactly that. Operator thought it was really cool till it started knocking.
On the Alaskan pipeline cat made special oil pans for d9s to operate on slopes they must have blown a few engines
My 977L is from the pipeline. There's a twin to it just down the street from where I work in Prudhoe. It's in awesome shape for having ~12,000hr meter hours. Pretty sure engine isn't on orginal parts.
tb135 looks like a standard pump and pickup and pan. like what you would see in a common car engine