Mahle develops oil-free compressors for CV brake systems

by Autocar Pro News Desk , 14 Aug 2018


Mahle's new oil-free compressor PCU.

Mahle, development partner and supplier to the automotive industry, has announced development of new components for the design of oil-free compressors.

These, it says, represent a small revolution in the production of compressed air for commercial vehicle brake systems. Thanks to the use of a Nikasil-coated cylinder in combination with a special Teflon piston ring and a sliding lacquer piston coating on the piston skirt, oil lubrication — previously a crucial step— can be omitted without any impact on the service life.

The advantages are clean, oil-free compressed air flow, low maintenance costs, low weight, and low frictional resistance because no oil control ring is necessary. Mahle offers the piston, piston ring, and cylinder as a complete unit.

For the compressor manufacturer, this means minimal systems weight with the use of aluminium pistons and cylinders, optimal temperature control of the perfectly harmonised components, and high durability.

Taking it a step further, the new components make it possible to physically separate the compressor from the gear drive of the combustion engine and power it via an electric 48-volt Mahle drive that can be controlled to meet demand. This not only minimises background noise but also achieves a measurable reduction in CO2, depending on the driving situation.

This, according to Mahle, is ideal for future use in battery electric vehicles, which cannot draw on an existing engine oil reservoir like vehicles with a combustion engine. The Nikasil coating, PTFE piston rings, and sliding lacquer piston coating on the piston skirt also offer advantages for manufacturers who would like to continue using oil-lubricated compressors for the time being, because they reduce the compressor’s oil consumption, friction, and weight.