Equipment World Digital Magazine
Issue link: https://read.dmtmag.com/i/473140
EquipmentWorld.com | March 2015 67 technology | by Tom Jackson | TomJackson@randallreilly.com H ave you ever operated a wheel loader that was perfect in some ap- plications, but less than ideal in others? Imagine if you could simply program the machine to operate one way in the morning, then just tap out a few choices on the in-cab monitor and have it react with a completely dif- ferent feel that afternoon. That was the goal behind the development of the Caterpillar 938K wheel loader. Scott Britton, product application specialist, likes to refer to this capability as changing the "personality" of the machine. Choose how it feels When the K series 938 wheel load- ers were introduced in 2012 the loader drivetrain operated with a feel between a traditional hydro- static drive and a powershift trans- mission. CAT engineers continued to work to make the loader even more refi ned based on customer feedback. In early 2014 they offered an in-cab programmable choice between a hystat operating mode or a mode that gave the machine the same feel and response as a torque converter model. Even though the machine is hydrostatic, meaning there was no torque converter mediating power between the engine and the drive- line, the default mode was "torque converter" because that's the "feel- ing" most wheel loader operators are familiar with. In the torque converter mode, the software in the loader's computer instructs the hydraulic system to op- erate like a torque converter model, with rolling stops and power to the ground coming on and off with a smoother transition. But hystat loaders are known for their aggressive digging and direc- tion changes with dynamic braking capable of holding the machine on Hydraulics and advanced software programming can change Cat's 938K from a pile punching machine to fi n- gertip fi nesse – and back again – with just a few taps on a screen The programmable wheel loader For aggressive work digging and loading trucks in a V-pattern, you can run in the hystat mode.