Hydraulic energy recovery system with dual-powered auxiliary hydraulics

A braking energy recovery system for use on a vehicle having a powertrain with a driving portion that includes an engine, and with a driven portion that includes a transmission and a driveshaft connecting the transmission to a wheelset, the driving portion of the powertrain being disengageably coupled to the driven portion, the braking energy recovery system comprising:

• a first pump, being a variable displacement hydraulic pump, coupled to the driven portion of the powertrain;
• a hydraulic accumulator connected to receive hydraulic fluid from the first pump, the accumulator being operative to store hydraulic fluid under pressure;
• a hydraulic motor connected to receive hydraulic fluid from the accumulator, the hydraulic motor being isolated from the driven portion of the powertrain such that they can turn independently, the hydraulic motor also being coupled to the driving portion of the powertrain;
• an auxiliary hydraulic system;
• and a second hydraulic pump adapted to power the auxiliary hydraulic system, the second hydraulic pump being coupled to the hydraulic motor, such that it can be operated by the hydraulic motor.