Utility vehicle with a continuously variable transmission having a system for selectively establishing a fixed maximum transmission ratio

摘要

A continuously variable transmission for a vehicle comprises a primary pulley, a secondary pulley, and a belt entrained around both pulleys in an opposite manner between the fixed and movable sheaves thereof. One pulley carries a selectively deployable stop that may be placed into position to mechanically limit the range of motion between the fixed and movable sheaves. This establishes an actual maximum transmission ratio that is larger than the nominal minimum transmission ratio but smaller than the nominal maximum transmission ratio achievable by the transmission during normal operation thereof. When such a transmission is used on a utility vehicle attached to a substance dispensing applicator operatively driven by the vehicle's engine, the application rate stays substantially constant despite changes in engine speed when the user keeps the transmission upshifted to the actual maximum transmission ratio set by the position of the deployed stop.

主权项

1. A belt type continuously variable transmission for the traction drive train of a vehicle, which comprises:
(a) at least one pulley comprising an axially fixed sheave and an axially movable sheave carried on a rotatable shaft; (b) a flexible belt that engages between the sheaves; (c) a plurality of movable members that are responsive to centrifugal force for pushing the fixed sheave towards the movable sheave to thereby change the position of the belt between the sheaves to continuously change a transmission ratio provided by the transmission between a nominal minimum transmission ratio and a nominal maximum transmission ratio; and (d) a selectively deployable stop carried on the at least one pulley with the stop being selectively movable relative to the sheaves between a non-deployed position and at least one deployed position, the stop being configured such that in the non-deployed position thereof the stop has no effect on the transmission ratios available from the transmission such that the transmission can continuously shift between its nominal minimum and maximum transmission ratios, the stop being further configured such that in the at least one deployed position thereof the stop is repositioned on the at least one pulley to mechanically limit the relative motion between the fixed and movable sheaves to a range of motion that is smaller than a range of motion provided in normal operation of the transmission but without the stop protruding into the path of or interfering with the operation of the centrifugal force responsive members, wherein the stop in the at least one deployed position thereof provides an actual maximum transmission ratio that is lower than the nominal maximum transmission ratio but higher than the nominal minimum transmission ratio with the centrifugal force responsive members still being able to operate to continuously shift the transmission between the nominal minimum transmission ratio and the actual maximum transmission ratio set by the position of the stop in the at least one deployed position thereof.