Abstract: In one aspect, a tensioner is provided, comprising, a first tensioner arm and a second tensioner arm, a first wheel and a second wheel. The first tensioner arm is pivotable about a first pivot axis. The second tensioner arm is pivotally connected to the first arm so as to be pivotable about a second pivot axis located at a selected distance from the first pivot axis. The first wheel is rotationally connected to the first tensioner arm about a first rotation axis. The second wheel is rotationally connected to the second tensioner arm about a second rotation axis. The first and second wheels are configured to engage an endless drive member. The first and second wheels are biased in respective first and second free arm directions.

Abstract: In one aspect, a tensioner is provided, comprising, a first tensioner arm and a second tensioner arm, a first wheel and a second wheel. The first tensioner arm is pivotable about a first pivot axis. The second tensioner arm is pivotally connected to the first arm so as to be pivotable about a second pivot axis located at a selected distance from the first pivot axis. The first wheel is rotationally connected to the first tensioner arm about a first rotation axis. The second wheel is rotationally connected to the second tensioner arm about a second rotation axis. The first and second wheels are configured to engage an endless drive member. The first and second wheels are biased in respective first and second free arm directions.

Abstract: A Y-tensioner is provided for tensioning the endless drive of an engine having a starter-generator unit (SGU). First and second arms of the Y-tensioner are pivotable about a common first axis. The second arm is articulated to the first arm and spring-loaded to pivot about a second axis spaced from the first axis. The first arm tensions a first strand of the endless drive which becomes the tight side when the SGU operates as a starter and the second arm tensions the second strand which becomes the tight side when the SGU operates as a generator. Pivoting of the Y-tensioner about the first axis enables the first or second arm to better align with the dominant force on the pulleys as the SGU shifts between starter and generator modes, reducing torque about the second axis to reduce the size of the spring that tensions the two arms together.