Background

Our customer, one of the world’s largest manufacturers of heavy buses and coaches, were looking for a new solution to power the compressor for air conditioning and, as it would turn out, also for compressed air in their hybrid buses. The unit was to be powered by the 600 VDC supply provided by the hybrid electric drive system.

Challenge

The unit is working in a wide geographical area – from cold cities to warm countries and high altitude with thinner air and less cooling effect. It is situated in a very rough environment, exposed to dust, rain and snow. Another challenge in this project was the limited space available for the unit.

Workflow

We have been cooperating with the customer for a couple of years and at one particular time the question about the air conditioning compressor came up. At Aros we had an existing system, satisfying approximately the same criteria, so we started to adjust the specifications to adapt a unit for this purpose. As the process went on the question about the compressed air was mentioned and we had a combined function project on our hands.

Achieved benefits

• A new compact unit, mounted just behind the rear wheels on the bus chassis.
• A highly integrated motor/drive system capable of operating in rough environments
• The same unit can be used for both the compressors for compressed air and air conditioning.
• Customised design with low weight and ease of installation.
• Useful feedback of a number of parameters for error diagnostics;