| US 7,510,495 B2 | ||
| Automatic speed reducing ratio-switching apparatus | ||
| Shigekazu Nagai, Tokyo (Japan); Akio Saitoh, Kawaguchi (Japan); Ryuichi Masui, Bando (Japan); and Masaki Imamura, Moriya (Japan) | ||
| Assigned to SMC Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Aug. 18, 2006, as Appl. No. 11/465,490. | ||
| Claims priority of application No. 2005-248330 (JP), filed on Aug. 29, 2005; and application No. 2005-338743 (JP), filed on Nov. 24, 2005. | ||
| Prior Publication US 2007/0049453 A1, Mar. 01, 2007 | ||
| Int. Cl. F16H 47/08 (2006.01) | ||
| U.S. Cl. 475—91 [475/263; 475/266; 475/299; 475/344] | 10 Claims |
| 1. An automatic speed reducing ratio-switching apparatus comprising:
a planetary gear mechanism including an input shaft and an output shaft, said planetary gear mechanism further including a
sun gear, planet gears, and an internal gear, each of which are helical gears, and a carrier that rotatably supports said
planet gears and which is integrally rotated in accordance with revolution of said planet gears;
a viscous resistance member, which is provided within an inner section of said carrier internally inserted into said internal
gear, said planet gears, and said internal gear, and which generates a thrust force between said internal gear and said planet
gears; and
a brake mechanism that causes said internal gear to be displaced in parallel by said thrust force, in a direction toward said
input shaft or a direction toward said output shaft, in accordance with increase or decrease in output load, in order to brake
rotational motion of said internal gear,
wherein a helix angle θ of each of said helical gears making up said sun gear, said planet gears, and said internal gear,
is not less than 25 degrees and not more than 45 degrees.
|