| 摘要 |
PROBLEM TO BE SOLVED: To provide a friction roller type reduction gear capable of reducing a weight and inertia force by reducing the number of components while securing high power transmission efficiency by suppressing friction loss, and further improving assemblability.SOLUTION: A friction roller reduction gear 100 includes a sun roller 15 disposed coaxially with an input shaft 11, a ring roller 17, a plurality of intermediate rollers 19 kept into contact with the sun roller and the ring roller while rolling, a connection portion 21 for connecting the ring roller and an output shaft, and a loading cam mechanism 23. The ring roller is composed of a pair of ring roller elements arranged in parallel with each other in an axial direction of the input shaft, and respectively having inner peripheral faces composed of inclined planes. The loading cam mechanism is disposed only at an outer end face side of one of the pair of ring roller elements. A roller holding portion is provided with a retaining ring 47 for axially positioning and restricting the other ring roller element to an axial end portion opposed to a basic end portion. The retaining ring has a spring portion 48 for axially pre-loading the other ring roller element.SELECTED DRAWING: Figure 2 |
