Work vehicle
A work vehicle includes: a body; left and right front wheels provided for the body; and left and right rear crawler units provided for the body. The rear crawler units each include: a drive wheel provided for a rear axle of the work vehicle; a front idler wheel forward of the drive wheel; a rear idler wheel backward of the drive wheel; a plurality of roller wheels between the front idler wheel and the rear idler wheel; a crawler belt wound around the drive wheel, the front idler wheel, the rear idler wheel, and the plurality of roller wheels; a track frame swingable about a swing shaft that extends in a left-right direction of the body and holding the front idler wheel, the rear idler wheel, and the plurality of roller wheels; and a position change mechanism configured to move the swing shaft in a front-back direction of the body.
1. A work vehicle, comprising:
a body;
left and right front wheels provided for the body; and
left and right rear crawler units provided for the body,
the rear crawler units each including:
a drive wheel provided for a rear axle of the work vehicle;
a front idler wheel forward of the drive wheel;
a rear idler wheel backward of the drive wheel;
a plurality of roller wheels between the front idler wheel and the rear idler wheel;
a crawler belt wound around the drive wheel, the front idler wheel, the rear idler wheel, and the plurality of roller wheels;
a track frame swingable about a swing shaft that extends in a left-right direction of the body and holding the front idler wheel, the rear idler wheel, and the plurality of roller wheels;
a position change mechanism configured to move the swing shaft in a front-back direction of the body, and
the position change mechanism includes an actuator to move the swing shaft.
2. The work vehicle according to claim 1 , wherein the position change mechanism is configured to move the swing shaft in the front-back direction of the body between (i) a front position, at which a center of the swing shaft is forward of a center of the rear axle, and (ii) a back position, at which the center of the swing shaft is backward of the center of the rear axle.
3. The work vehicle according to claim 1 , wherein
the swing shaft is below the rear axle, and
the actuator is between the rear axle and the swing shaft in a side view.
4. The work vehicle according to claim 1 , wherein
the actuator includes a hydraulic cylinder configured to extend and contract in the front- back direction of the body.
5. A work vehicle, comprising:
a body;
left and right front wheels provided for the body; and
left and right rear crawler units provided for the body,
the rear crawler units each including:
a drive wheel provided for a rear axle of the work vehicle;
a front idler wheel forward of the drive wheel;
a rear idler wheel backward of the drive wheel;
a plurality of roller wheels between the front idler wheel and the rear idler wheel;
a crawler belt wound around the drive wheel, the front idler wheel, the rear idler wheel, and the plurality of roller wheels;
a track frame swingable about a swing shaft that extends in a left-right direction of the body and holding the front idler wheel, the rear idler wheel, and the plurality of roller wheels, the swing shaft being movable in a front-back direction of the body;
an actuator configured to move the swing shaft; and
a control device configured to control how the actuator is driven.
6. The work vehicle according to claim 5 , wherein
the control device causes the actuator to move the swing shaft in the front-back direction of the body between (i) a front position, at which a center of the swing shaft is forward of a center of the rear axle, and (ii) a back position, at which the center of the swing shaft is backward of the center of the rear axle.
7. The work vehicle according to claim 5 , wherein
the control device has, as a control mode for controlling how the actuator is driven, an automatic control mode, in which the control device controls how the actuator is driven in accordance with a turn of the body.
8. The work vehicle according to claim 7 , further comprising:
an operation switch for use to drive the actuator,
wherein the control device has, as the control mode, a manual control mode, in which the control device controls how the actuator is driven in response to a manual operation of the operation switch.
9. The work vehicle according to claim 5 , wherein
the actuator includes a hydraulic cylinder configured to extend and contract in the front-back direction of the body.