Rocking type exercising apparatus

1. A rocking exercising apparatus comprising:

a movable unit on which a user rides; and

a driving unit for causing the movable unit to perform a rocking motion,

wherein the driving unit is capable of driving the movable unit to rock in forward/backward directions of the user riding on the movable unit and capable of moving the movable unit forward at a greater acceleration than when the movable unit is moved backward;

wherein the driving unit includes a movable frame, a motor arranged within the movable frame, an output shaft to which torque of the motor is transferred, and a first and a second link plate for connecting the movable unit to the movable frame;

wherein the output shaft has a first and a second off-centered portion lying on an external surface of the movable frame;

wherein eccentric rotation of the first off-centered portion causes a front end of the movable unit to swing in the forward/backward directions through the second link plate; and

wherein eccentric rotation of the second off-centered portion causes a rear end of the movable unit to swing in the forward/backward directions through the first link plate.

2. The rocking exercising apparatus of claim 1 , wherein the driving unit is designed to rock the movable unit by using eccentric rotational output powers and to set an acceleration difference between forward movement and backward movement by using the eccentric rotations.

3. The rocking exercising apparatus of claim 1 , wherein the first link plate is connected to the rear end of the movable unit and joined together with the movable unit by a first joint shaft, and the second link plate is connected to the front end of the movable unit through an extensible/contractible actuator joined together with the movable unit by a second joint shaft.

4. The rocking exercising apparatus of claim 1 , wherein the first off-centered portion is connected to the second link plate and the second off-centered portion is connected to one end of a connection link of which the other end is connected to the first link plate.

5. The rocking exercising apparatus of claim 3 , wherein the eccentric rotation of the first off-centered portion causes the front end of the movable unit to swing in the forward/backward directions through the second link plate and the extensible/contractible actuator.

6. The rocking exercising apparatus of claim 4 , wherein the eccentric rotation of the second off-centered portion causes the rear end of the movable unit to swing in the forward/backward directions through the connection link and the first link plate.

7. The rocking exercising apparatus of claim 1 , wherein the first off-centered portion has reduced eccentricity, while the second off-centered portion has increased eccentricity.