Track tensioning assembly for adjusting tension on a drive track chain of a work machine having an actuator which includes a pair of concentrically arranged pistons

An undercarriage assembly of a work machine, comprising:

• an idler wheel;
• a drive track chain which is advanced around said idler wheel;
• and
• a track tensioning assembly for adjusting tension on said drive track chain, said track tensioning assembly having:
• (i) a main housing defining a main chamber,
• (ii) a recoil piston positioned within said main chamber, said recoil piston having a recoil central passage defined therein,
• (iii) a master piston positioned within said recoil central passage, said master piston (a) increases fluid pressure in said main chamber when said master piston is positioned in a first master position, and (b) decreases fluid pressure within said main chamber when said master piston is positioned in a second master position, and
• (iv) a slave piston having a first end positioned within said main chamber and a second end extending out of said main housing so as to be mechanically coupled to said idler wheel, said slave piston (a) urges said idler wheel in a first direction so as to increase tension on said drive track chain when said slave piston is positioned in a first slave position, and (b) urges said idler wheel in a second direction so as to decrease tension on said drive track chain when said slave piston is positioned in a second slave position,
• wherein movement of said master piston from said first master position to said second master position causes movement of said slave piston from said first slave position to said second slave position.

A work machine, comprising:

• an idler wheel;
• a drive track chain which is advanced around said idler wheel;
• and
• a track tensioning assembly for adjusting tension on said drive track chain, said track tensioning assembly having:
• (i) a main housing defining a main chamber,
• (ii) a master piston positioned within said main chamber, said master piston (a) increases fluid pressure in said main chamber when said master piston is positioned in a first master position, and (b) decreases fluid pressure within said main chamber when said master piston is positioned in a second master position, and
• (iii) a slave piston having a first end positioned within said main chamber and a second end extending out of said main housing so as to be mechanically coupled to said idler wheel, said slave piston (a) urges said idler wheel in a first direction so as to increase tension on said drive track chain when said slave piston is positioned in a first slave position, and (b) urges said idler wheel in a second direction so as to decrease tension on said drive track chain when said slave piston is positioned in a second slave position;
• a hydraulic drive system for driving said drive track chain, said hydraulic system is operable in (i) an actuated mode of operation in which said hydraulic drive system drives said drive track chain, and (ii) a deactuated mode of operation in which said hydraulic drive system is idle,
• wherein (i) said master piston is positioned in said first master position when said hydraulic drive system is operated in said deactuated mode of operation, (ii) said master piston is positioned in said second master position when said hydraulic drive system is operated in said actuated mode of operation, and (iii) movement of said master piston from said first master position to said second master position causes movement of said slave piston from said first slave position to said second slave position.