Cab forward eases operation
For its D51-22 dozers, Komatsu completely re-arranged the traditional dozer configuration by using a cab-forward design with a Super Slant nose. Then it followed suit with its D39-22, D37-22 and D31-22 models.
The cab-forward design would not have been possible with a traditional dozer design, since it is essential to keep the tractor balanced. ?One of the advantages of having a new ground up design is you have a clean slate from which to start,? says Bruce Boebel, product marketing manager - dozers, Komatsu America Corp.
A cab-forward design ? which moves the operator about 2 ft. forward on the machine ? has several advantages. ?With the smaller machines, the operators are more productive,? says Boebel. ?They are able to see obstacles a lot sooner. They are able to react a lot quicker, especially in tight spots. You can easily take a younger operator, put him in our machine and he is going to get up to speed a lot faster. The learning curve is a lot less.?
Operator placement on the machine also influences comfort. ?You are actually more forward on the machine, which is closer to the center of balance. The end result is you are not getting jarred as bad in the rear of the machine as in the past,? Boebel comments.
To aid visibility even further, the cooling package has been moved to the back of the tractor and the nose is steeply sloped. This also allows for increased cooling efficiency. ?We have an electronically-controlled, hydraulically-driven fan,? Boebel explains. ?Basically, it runs only at the speed it needs to; therefore, it is more efficient. We had enough room open up that we could put all of the coolers side by side so they are not stacked, increasing cooling efficiency.?
In addition, these dozers use new generation hydrostatic transmissions. For example, past drive motor designs had three steps or positions that would abruptly shift under varying loads, says Boebel. ?Our drive motors are now infinitely variable along with the hydrostatic pumps, so they don?t lose pushing power in turns with a heavy load on the blade,? he states. ?It increases productivity and fuel economy, as well. The machine is always running at optimum performance.?