| 摘要 |
PROBLEM TO BE SOLVED: To achieve automatic gear shifting according to load torque of an output shaft with very simple structure, and thereby to reduce a size and a production cost of a device.SOLUTION: An automatic transmission includes: an input shaft 1; the output shaft 2 concentric with the input shaft 1; conical cones 3 rotating while revolving about the input and output shafts; a gear shift ring 4 frictionally-engaged with the cones 3; a contact-pressure applying means 23 applying contact pressure between the cones 3 and the gear shift ring 4; a moving means 5 moving the gear shaft ring 4 forward and backward in an axial direction of the input and output shafts; a biasing means 6 biasing the forward and backward movement of the gear shift ring 4. Each of the cones 3 is disposed so that a rotation axis 3d of the cone does not intersect with a rotation axis of the input and output shafts. When the load torque is generated in the output shaft 2, a gear shift force acts in the axial direction of the input and output shafts with respect to the gear shift ring 4. The biasing means 6 is set so that a biasing force opposite in direction to the gear shift force is operated with preset output characteristics. |
