Drive device for electric vehicle and electric vehicle

A drive device for an electric vehicle, the drive device comprising:

• a motor configured to be installed at a position adjacent to a drive wheel of the electric vehicle;
• a reduction gear configured to reduce rotational speed of the motor and transmit resultant rotation to the drive wheel;
• and
• a reduction gear housing that accommodates the reduction gear,
• the reduction gear comprising:
• a sun gear configured to be driven by the motor;
• a first planetary gear that is configured to be meshed with the sun gear and has a first number of teeth;
• a fixed ring gear that is meshed with the first planetary gear and arranged non-rotatably;
• a second planetary gear that is coupled to the first planetary gear and has a second number of teeth that is smaller than the first number of teeth;
• a movable ring gear that is meshed with the second planetary gear and arranged rotatably;
• and
• a transmission member configured to transmit rotation of the movable ring gear to the drive wheel,
• wherein:
• the motor is configured to be further toward a center side of the electric vehicle than a disk portion of a wheel of the drive wheel;
• the reduction gear housing is configured to be between motor and the disk portion;
• the first planetary gear and the second planetary gear are helical gears with opposite helix angles;
• the first planetary gear and the second planetary gear have a first helix angle and a second helix angle, respectively, which satisfy β2=tan−1{(P1/P2)·tan(β1)};
• β1 represents the first helix angle of the first planetary gear;
• P1 represents a first tangential force produced in accordance with the first helix angle;
• β2 represents the second helix angle of the second planetary gear;
• and
• P2 represents a second tangential force produced in accordance with the second helix angle.

A drive device for an electric vehicle, the drive device comprising:

• a motor configured to be installed at a position adjacent to a drive wheel of the electric vehicle;
• a reduction gear configured to reduce rotational speed of the motor and transmit resultant rotation to the drive wheel;
• an axle housing that accommodates the motor;
• a reduction gear housing that accommodates the reduction gear and is coupled to the axle housing;
• and
• a tire shaft having a tubular shape and being configured to couple the drive wheel and the reduction gear to each other,
• the reduction gear comprising:
• a sun gear configured to be driven by the motor;
• a first planetary gear that is configured to be meshed with the sun gear and has a first number of teeth;
• a fixed ring gear that is meshed with the first planetary gear and arranged non-rotatably;
• a second planetary gear that is coupled to the first planetary gear and has a second number of teeth that is smaller than the first number of teeth;
• a movable ring gear that is meshed with the second planetary gear and arranged rotatably;
• a transmission member configured to transmit rotation of the movable ring gear to the drive wheel;
• a plurality of composite planetary gears, each of which includes the first planetary gear and the second planetary gear coupled to each other;
• a carrier member that defines an interval between the plurality of composite planetary gears arranged around the sun gear, the carrier member including:
• a plurality of shaft portions extending along rotation shafts of the plurality of composite planetary gears, respectively;
• a plate-shaped first coupling portion to which a first end portion of each of the plurality of shaft portions is coupled;
• and
• a plate-shaped second coupling portion to which a second end portion of each of the plurality of shaft portions is coupled;
• and
• a plurality of bearings rotatably supporting the plurality of shaft portions, respectively,
• wherein:
• an oil path is defined inside each of the plurality of shaft portions for guiding lubricating oil to the bearing supporting the shaft portion from an oil supply port defined in the first end portion or the second end portion of the shaft portion;
• and
• at least one of the transmission member or the reduction gear housing has a nozzle portion at a position facing the oil supply port and configured to inject the lubricating oil toward the oil supply port.

A drive device for an electric vehicle, the drive device comprising:

• a motor configured to be installed at a position adjacent to a drive wheel of the electric vehicle;
• a reduction gear configured to reduce rotational speed of the motor and transmit resultant rotation to the drive wheel;
• and
• a reduction gear housing that accommodates the reduction gear,
• the reduction gear comprising:
• a sun gear configured to be driven by the motor;
• a first planetary gear that is configured to be meshed with the sun gear and has a first number of teeth;
• a fixed ring gear that is meshed with the first planetary gear and arranged non-rotatably;
• a second planetary gear that is coupled to the first planetary gear and has a second number of teeth that is smaller than the first number of teeth;
• a movable ring gear that is meshed with the second planetary gear and arranged rotatably;
• a transmission member configured to transmit rotation of the movable ring gear to the drive wheel;
• a plurality of composite planetary gears, each of which includes the first planetary gear and the second planetary gear coupled to each other;
• a carrier member that defines an interval between the plurality of composite planetary gears arranged around the sun gear, the carrier member including:
• a plurality of shaft portions extending along rotation shafts of the plurality of composite planetary gears, respectively;
• a plate-shaped first coupling portion to which a first end portion of each of the plurality of shaft portions is coupled;
• and
• a plate-shaped second coupling portion to which a second end portion of each of the plurality of shaft portions is coupled;
• and
• a plurality of bearings rotatably supporting the plurality of shaft portions, respectively,
• wherein:
• the motor is configured to be further toward a center side of the electric vehicle than a disk portion of a wheel of the drive wheel;
• the reduction gear housing is configured to be between motor and the disk portion;
• an oil path is defined inside each of the plurality of shaft portions for guiding lubricating oil to the bearing supporting the shaft portion from an oil supply port defined in the first end portion or the second end portion of the shaft portion;
• and
• at least one of the transmission member or the reduction gear housing has a nozzle portion at a position facing the oil supply port and configured to inject the lubricating oil toward the oil supply port.