Driving system and electric vehicle comprising the same

摘要

A driving system of an electric vehicle and an electric vehicle comprising the same are provided. The driving system comprises: a driving motor, a transmission and a hydraulic system. The transmission may include an input shaft, an output shaft, a first transmission unit, a first clutch, a second transmission unit and a second clutch.

主权项

1. A driving system for an electric vehicle, comprising:
a driving motor; a transmission including,
an input shaft connected to the driving motor,an output shaft,a first transmission unit having a first transmission ratio and connected to the input shaft and the output shaft, respectively, to transmit first power therebetween,a first clutch disposed on the input shaft and connected to the first transmission unit, for connecting and disconnecting the first power transmission between the input shaft and the first transmission unit,a second transmission unit having a second transmission ratio smaller than the first transmission ratio and connected to the input shaft and the output shaft, respectively, to transmit second power therebetween,a second clutch disposed on the input shaft and connected to the second transmission unit, for connecting and disconnecting the second power transmission between the input shaft and the second transmission unit; and a hydraulic system connected to the first clutch and the second clutch, respectively, for engaging/disengaging the first clutch to/from the first transmission unit and for engaging/disengaging the second clutch to/from the second transmission unit, respectively, wherein the hydraulic system comprises: an oil container; a first clutch driving circuit including a first driving hydraulic cylinder having a piston connected to a driving part of the first clutch, and a first proportional valve connected to the first driving hydraulic cylinder and the oil container, respectively; a second clutch driving circuit in parallel connection with the first clutch driving circuit, and including a second driving hydraulic cylinder having a piston connected to a driving part of the second clutch, and a second proportional valve connected to the second driving hydraulic cylinder and the oil container, respectively; an internal pump driven by the output shaft and having an inlet coupled to the oil container, and an outlet coupled to the first and second proportional valve respectively; a first check valve connected in series to the outlet of the internal pump; an external pump driven by an external pump motor and having an inlet coupled to the oil container and an outlet coupled to the first and second proportional valve respectively; a second check valve connected in series to the outlet of the external pump, wherein the first check valve and the internal pump which are connected in series, and the second check valve and the external pump which are connected in series, are connected in parallel between the oil container and the first clutch driving circuit as well as the second clutch driving circuit; and a third check valve connected in parallel with the external pump.