Vibration damping assembly
View Patent ↗A vibration damping assembly may be used with a lawn tractor to reduce vibrations caused by operation of a mower deck. A pulley belt drive system includes a pulley belt connecting a drive pulley to one or more driven pulleys. The vibration damping assembly includes a first idler pulley and a second idler pulley to dampen associated vibrations caused during operation of the mower deck. The vibration damping assembly further includes biasing means, such as springs, to keep the first and second idler pulleys in contact with the pulley belt.
1. A vibration damping mechanism for use with a lawn tractor adapted to reduce vibrations caused by operation of vegetation cutting blades of the tractor, the lawn tractor having a frame, an engine and a mower deck supported by said frame, said mower deck having at least first and second cutting blades mounted beneath the deck and first and second blade pulleys operatively connected to said first and second cutting blades, respectively, and a drive system comprising a drive pulley connected to a crankshaft of said engine and a drive belt operatively connecting said first and second blade pulleys to said drive pulley for transferring rotational energy from the drive pulley to said first and second blade pulleys, thereby causing rotation of said first and second cutting blades for cutting vegetation, the vibration damping mechanism comprising:
a first idler pulley for placing tension in said belt having a first spring biasing said first idler pulley into engagement with said belt, wherein said first idler pulley is positioned so as to contact said belt in a slack portion of said belt between the drive pulley and the first blade pulley; and
a second idler pulley for reducing vibrations of said belt having a second spring biasing said second idler pulley in engagement with said belt, wherein said second idler pulley is positioned so as to contact said belt in a tension portion of the belt between the second blade pulley and the drive pulley.
2. The vibration damping mechanism of claim 1 wherein the biasing tension force of the first spring is within ±15% of the biasing tension force for the second spring.
3. The vibration damping mechanism of claim 1 wherein said vibration damping mechanism further comprises first and second pulley arms operatively connected to said first and second idler pulleys, respectively, wherein said first and second pulley arms further comprise an opening for receiving an associated tool.
4. The vibration damping mechanism of claim 1 wherein the position of said first idler pulley is elevated relative to the position of said second idler pulley.
5. The vibration damping mechanism of claim 1 further comprising first and second pulley arms operatively connected to said first and second idler pulleys, respectively, wherein said first and second idler pulley arm are pivotably attached to said deck, and further comprising stopping means positioned with respect to said pulley arms so as to limit the amount of pivoting of said first and second pulley arms.
6. The vibration damping mechanism of claim 1 wherein the first and second springs are substantially identical springs.
7. A lawn tractor comprising the vibration damping mechanism of claim 1 .