A propulsion device for a bicycle can include a mounting assembly for releasably coupling the propulsion device to the bicycle, a motor, a power source selectively providing power to the motor, a gear assembly, and two frictional drive components coupled to the gear assembly. The two frictional drive components can be movable between an engaged configuration and a disengaged configuration. In the engaged configuration, the two frictional drive components are frictionally engaged with a side of a wheel of the bicycle such that the wheel is arranged between the two frictional drive components. In the disengaged configuration the two frictional drive components are disengaged from the wheel. The motor can drive the gear assembly: (i) to move the two frictional drive components into the engaged configuration, and (ii) to rotate at least one of the two frictional drive components to rotate the wheel of the bicycle.

A propulsion device for a bicycle can include a mounting assembly for releasably coupling the propulsion device to the bicycle, a motor, a power source selectively providing power to the motor, a gear assembly, and two frictional drive components coupled to the gear assembly. The two frictional drive components can be movable between an engaged configuration and a disengaged configuration. In the engaged configuration, the two frictional drive components are frictionally engaged with a side of a wheel of the bicycle such that the wheel is arranged between the two frictional drive components. In the disengaged configuration the two frictional drive components are disengaged from the wheel. The motor can drive the gear assembly: (i) to move the two frictional drive components into the engaged configuration, and (ii) to rotate at least one of the two frictional drive components to rotate the wheel of the bicycle.

A multidirectional wheel system, apparatus, and method to control one or more multidirectional wheels to provide multidirectional motion or movement for a movable apparatus, such as a skateboard, roller blades, a car, a motorcycle, a cleaning robot, to which the one or more multidirectional wheels are attached. The multidirectional wheel system can include a braking system to slow and/or stop the movement of the multidirectional wheel(s). At least one of the multidirectional wheels can be an omnidirectional wheel(s), with a plurality of multidirectional wheels acting thereon to control movement thereof.

A multidirectional wheel system, apparatus, and method to control one or more multidirectional wheels to provide multidirectional motion or movement for a movable apparatus, such as a skateboard, roller blades, a car, a motorcycle, a cleaning robot, to which the one or more multidirectional wheels are attached. The multidirectional wheel system can include a braking system to slow and/or stop the movement of the multidirectional wheel(s). At least one of the multidirectional wheels can be an omnidirectional wheel(s), with a plurality of multidirectional wheels acting thereon to control movement thereof.

The power assisting device includes driver with a rotary axis, a main gear, a first transmission rod, a first bevel gear, a second bevel gear, a first rotating rod, a third bevel gear, and a first driving wheel. The main gear is driven by the driver to rotate about the rotary axis. The first transmission rod extends along a direction perpendicular to the rotary axis. The first bevel gear and the second bevel gear are separately sleeved on the transmission rod. The first bevel gear is engaged with the main gear. The first rotating rod extends along a direction parallel to the rotary axis. The third bevel gear is sleeved on the first rotating rod and is engaged with the second bevel gear. The first driving wheel is coupled to the first rotating rod for assisting a wheel of a vehicle to move forward.

The power assisting device includes driver with a rotary axis, a main gear, a first transmission rod, a first bevel gear, a second bevel gear, a first rotating rod, a third bevel gear, and a first driving wheel. The main gear is driven by the driver to rotate about the rotary axis. The first transmission rod extends along a direction perpendicular to the rotary axis. The first bevel gear and the second bevel gear are separately sleeved on the transmission rod. The first bevel gear is engaged with the main gear. The first rotating rod extends along a direction parallel to the rotary axis. The third bevel gear is sleeved on the first rotating rod and is engaged with the second bevel gear. The first driving wheel is coupled to the first rotating rod for assisting a wheel of a vehicle to move forward.