摘要 |
<p>A DRIVE UNIT A positive planetary drive having zero backlash interconnects coaxial input and output shafts in a drive unit. A plurality of rollers orbiting about the input shaft is always entrapped in rolling contact with a plurality of wedges supported by the output shaft. Cams in the drive unit provide cam surfaces contacted by orbiting rollers on the input shaft to provide a continuous constant velocity output motion at a speed which is less than the input motion. Intermittent motion is provided by cam surfaces engaged by the same rollers which contact the wedges. A gear drive engaged with a cam plate used to form the various cams provides a variable angular relationship between the input shaft and the output shaft. Protection against a torque overload at the output shaft is provided by permitting plungers to rotate with the cam plate when disengaged from seats supported by the housing.</p> |