Abstract: The compressor is inferiorly provided with a discharge nozzle and with shoes which are seated and affixed against a support plate, incorporated to the air-oil reservoir and provided with an admission hole aligned with the discharge nozzle, and with a tubular column, incorporated to the air-oil reservoir and open to the interior of the latter. The air-oil reservoir further presents: an inner housing receiving a thermostatic valve, connected to the interior of the air-oil reservoir and also to the compressor and to an oil radiator, as a separate device, through cold oil outlet and hot oil outlet nozzles of the air-oil reservoir; openings for the direct coupling of an oil filter and of an air-oil separating filter; and an end housing lodging a minimum pressure valve.