| 摘要 |
A gear with a controllable, continuously variable gear ratio comprises two fixedly mounted wheels 14, 15 on respective axles 2, 16, around which a chain 8, 9 or similar is running. The perimeter part of one wheel 14 in engagement with the chain is divided into separated, individual segments 4 distributed along the perimeter, and arranged at outer ends of arms 3 which for allowing change of the wheel diameter and thereby the gear ratio are journalled in the hub area 1 of the wheel 14, swingable around axles 5 extending in parallel with the wheel axle 2. The arms 3 are constantly swung out such in the same direction from a radial plane extending through associated swinging centres and the centre of the wheel, that they are kept swung out by the engagement between the chain 8, 9 and the segments 4, and the magnitude of the engagement force is dependent on the magnitude of the torque transmitted through the gear. For adjusting the gear ratio of the gear, a device 11 is provided for controllable, forced adjustment of the length of the portion of the chain accessible for encircling said one wheel 14. <IMAGE> |
