Two-speed transmission system integrated with inner rotor hub motor and electric vehicle using same

1. A two-speed transmission system integrated with an inner rotor hub motor, comprising:

• a hub motor casing;
• a motor shaft which is rotatably supported at a center of the hub motor casing, and an output end of the motor shaft extends out of the hub motor casing;
• a first sun gear which is fixedly connected to the output end of the motor shaft;
• a plurality of first planetary gears which are meshed with the first sun gear;
• a first inner ring gear which is meshed with the first planetary gears and fixedly connected to the hub motor casing;
• a first planetary carrier which is provided with a stepped hollow shaft and is rotatably supported on the motor shaft;
• a first planetary carrier cover which is rotatably supported on the motor shaft and fixedly connected to the first planetary carrier;
• a second sun gear which is fixedly connected to the first planetary carrier;
• a plurality of second planetary gears which are meshed with the second sun gear;
• a second inner ring gear which is meshed with the second planetary gears;
• a second planetary carrier;
• a second planetary carrier cover which is rotatably supported on the first planetary carrier and fixedly connected to the second planetary carrier;
• a first electromagnetic brake casing;
• a first excitation coil which is provided in a first annular groove;
• a first magnet yoke;
• a first spring which is provided in a first blind hole;
• a second electromagnetic brake casing which is fixedly connected to the second planetary carrier, and is circumferentially and uniformly provided with a plurality of second blind holes;
• a second excitation coil;
• a second magnet yoke;
• a second spring which is provided in the second blind hole;
• and
• a friction disk which is provided between the first magnet yoke and the second magnet yoke with clearance and fixedly connected to the second inner ring gear;
• wherein:
• the second inner ring gear is rotatably supported on the first electromagnetic brake casing;
• the first electromagnetic brake casing is circumferentially provided with the first annular groove;
• and a radially inner side of the first annular groove is circumferentially and uniformly provided with the first blind hole;
• a space is provided between the first magnet yoke and the first excitation coil;
• one end of the first spring abuts against a bottom of the first blind hole, and the other end of the first spring is fixedly connected to the first magnet yoke;
• a space is provided between the second excitation coil and the second electromagnetic brake casing;
• one end of the second spring abuts against a bottom of the second blind hole, and the other end of the second spring is fixedly connected to the second magnet yoke;
• and
• wherein the first excitation coil and the second excitation coil are selectively energized or de-energized to enable the friction disk to selectively press against the first magnet yoke or the second magnet yoke.