Question

Why are hydraulic systems better for large machines?

Answer 1

Hydraulic systems are better for large machines because they have high mechanical advantage, they can be sealed, and they are relatively easy to maintain.

Explanation:

Large machines need powerful components that can accommodate tremendous weights so they can deliver maximum payloads on construction sites or in service bays. Beside the payloads they carry, they may need to move themselves around the job site. Since they are such strong, heavy machines their own weight must be added to the mobility considerations in their design.

Hydraulic systems have been developed that use pistons to enhance Newton's lever forces to move the machine and its loads. With the use of hydraulics a smaller force can be applied to a piston resulting in a larger force operating at a smaller distance using the incomprehensibility property of hydraulic fluids.

Since these machine typically operate in dusty, greasy conditions with possibly extreme temperature variations, they must be well sealed from the environment and be capable of enduring harsh operation.

Maintenance of hydraulic systems usually involves big tools, plenty of hydraulic oil and sufficient hydraulic hoses, fittings, and jacks. Most problems can be rectified readily if equipment is at hand.

There are hydraulic machine images here:
http://ffden-2.phys.uaf.edu/212_spring2005.web.dir/annie_weber/page3.html