Continuously variable transmission engine braking system

A drive sheave assembly of a continuously variable transmission, the drive sheave assembly comprising:

• a post;
• a fixed sheave statically mounted on the post, the fixed sheave including a central recess, the fixed sheave further including a plurality of sheave ramps within the central recess;
• a movable sheave slidably mounted on the post;
• a sleeve rotatably mounted on the post, a mid-portion of the sleeve positioned between the fixed sheave and the movable sheave, the mid-portion of the sleeve including an outer surface configured engage an inner surface of a belt;
• a one-way engagement collar mounted over an end portion of the sleeve, the one-way engagement collar having a plurality of locking pockets extending axially in from a side edge of the one-way engagement collar, the one-way engagement collar including a plurality of roller windows, each roller window extending radially from an inside surface of the one-way engagement collar into an associated locking pocket, the one-way engagement collar further having a plurality of ramp pockets that extend axially in from an end surface of the one-way engagement collar;
• a plurality of pairs of locking rollers and roller biasing members, each pair of locking roller and roller biasing member of the plurality of the locking rollers and roller biasing members received in an associated locking pocket of the one-way engagement collar wherein a portion of each locking roller extends through an associated roller window of the one-way engagement collar to engage the portion of the sleeve, each locking pocket and associated pair of locking roller and roller biasing member being configured to allow rotation of the one-way engagement collar on the end portion of the sleeve when the sleeve rotates in a first direction and lock rotation of the one-way engagement collar onto the rotation of the sleeve when the sleeve rotates in a second direction;
• and
• a ramp member received within each ramp pocket of the plurality of ramp pockets in the one-way engagement collar, each ramp member configured to engage an associated sheave ramp of the plurality of sheave ramps in the central recess of the fixed sheave and move the one-way engagement collar axially to engage a side of the belt when the sleeve rotates in the second direction.

A vehicle comprising:

• a drivetrain;
• an engine;
• and
• a continuously variable transmission in operational communication between the drivetrain and the engine to couple torque between the engine and the drivetrain, the continuously variable transmission including at least one sheave assembly, the at least one sheave assembly further including,
• a post,
• a fixed sheave statically mounted on the post, the fixed sheave including a central recess, the fixed sheave further including a plurality of sheave ramps within the central recess;
• a movable sheave slidably mounted on the post,
• a sleeve rotatably mounted on the post, a mid-portion of the sleeve positioned between the fixed sheave and the movable sheave, the mid-portion of the sleeve having an outer surface configured to engage an inner surface of a belt,
• a one-way engagement collar mounted over an end portion of the sleeve, the one-way engagement collar configured to rotate freely on the end portion of the sleeve when the sleeve rotates in a first direction and lock onto rotation of the sleeve when the sleeve rotates in a second direction, the one-way engagement collar further having a plurality of ramp pockets that extend axially in from an end surface of the one-way engagement collar, and
• a ramp member received within each ramp pocket of the plurality of ramp pockets in the one-way engagement collar, each ramp member configured to engage an associated sheave ramp of the plurality of sheave ramps in the central recess of the fixed sheave and move the one-way engagement collar axially to engage a side of the belt when the sleeve rotates in the second direction.