Quick-connect mechanism for releasably retaining a power take-off shaft within an output shaft hub

A power take-off unit of off-highway equipment such as a tractor, comprising:

• an output shaft housed within the power take-off unit and adapted to be rotationally driven by gearing in said power take-off unit, said output shaft having a hollow, internally splined hub portion adapted to axially receive an externally splined power take-off shaft to prevent relative rotational movement between the power take-off and output shafts;
• a plurality of circumferentially spaced locking balls guided within respective spaced radial openings in the output shaft so as to be simultaneously radially movable between inner locking positions, wherein said locking balls are engageable with an annular groove formed on the power take-off shaft to prevent relative axial movement between the power take-off shaft and the output shaft, and outer unlocking positions, wherein said locking balls are disengaged from said groove in the power take-off shaft;
• an annular collar surrounding the output shaft and being axially movable between a first position in which an inner surface of the collar is generally in alignment with the radial openings in the output shaft to engage and operably maintain the locking balls in their inner locking position, and a second axially displaced position to permit outward radial movement of said locking balls to their outer unlocking position;
• and
• a bias member adapted to bias the collar toward the first position to normally maintain the collar in locking engagement with the locking balls.

In combination with a power take-off unit of a tractor having an output shaft for delivering power to agricultural implements and a reversible power take-off shaft releasably fixed to said output shaft, said output shaft having a hollow, internally splined hub portion adapted to axially receive an externally splined center section of the power take-off shaft to prevent relative rotational movement therebetween, a locking mechanism comprising:

• said output shaft having a plurality of circumferentially spaced radial openings formed in said hub portion;
• said power take-off shaft having an annular groove formed in the splined center section and being positionable within the hollow hub portion of the output shaft such that the groove is generally in alignment with the radial openings;
• a plurality of locking balls supported within respective ones of said radial openings for radial movement relative to the axis of the output shaft;
• an annular collar surrounding the output shaft and being axially movable between a first position in which an inner surface of the collar is generally in alignment with the radial openings in the output shaft to engage and operably maintain the locking balls in their inner locking position, and a second axially displaced position to permit outward radial movement of said locking balls to their outer unlocking position;
• and
• a spring surrounding a distal portion of the output shaft and being interposed between the collar and the output shaft to bias the collar toward the first position to normally maintain the collar in locking engagement with the locking balls;
• whereby the collar is axially movable against the action of the spring from said first position to said second position to permit outward radial movement of said locking balls to their unlocking position, thereby allowing removal of the power take-off shaft from the output shaft.