Drive and transmission for urban bus - has hydraulic energy storage system with two hydraulic converters, one for each driven wheel

摘要

The drive system, particularly for an urban bus has an engine (11) driven hydraulic pump (14) to store energy in a hydraulic reservoir (16). The output from the reservoir and the pump drives a hydraulic converter (17) linked to the output drive shaft (24). For regenerative braking the hydraulic motor acts as a pump and also primes the pressure reservoir. Additional fluid is drawn from and returned to a low pressure reservoir (21) to form a closed system. The engine runs at the most economic speed and is sufficient to drive the bus at maximum speed on flat ground. The energy store is used for starting or for negotiating hills.