A tensioner for adjusting a tension in an endless track of a track system is disclosed. The tensioner includes a resilient portion and a wheel connecting portion. The resilient portion is connectable to a frame of the track system, the resilient portion being oriented generally vertically. The wheel connecting portion is pivotally connectable to the frame of the track system, is connected to the resilient portion and is configured to connect to an idler wheel assembly. A track system having the tensioner is also disclosed.

A traveling operation device of a crawler-type aerial work platform including an operation of an enable switch by one hand is provided. An enable switch and a changeover switch are disposed on an operation rod main body at positions where the enable switch and the changeover switch are operable by fingers gripping the operation rod main body of an operation rod during traveling so that all of them are operable by one hand. When a controller receives a switching command signal in accordance with the operation of the changeover switch in a state of usual travel control according to tilt of the operation rod in front-rear and right-left directions, the controller stops the usual travel control to transition the usual travel control to spin turn control that rotates motors in mutually opposite directions and turns the platform on the spot.

A traveling operation device of a crawler-type aerial work platform including an operation of an enable switch by one hand is provided. An enable switch and a changeover switch are disposed on an operation rod main body at positions where the enable switch and the changeover switch are operable by fingers gripping the operation rod main body of an operation rod during traveling so that all of them are operable by one hand. When a controller receives a switching command signal in accordance with the operation of the changeover switch in a state of usual travel control according to tilt of the operation rod in front-rear and right-left directions, the controller stops the usual travel control to transition the usual travel control to spin turn control that rotates motors in mutually opposite directions and turns the platform on the spot.

A crawler traveling device includes a first wheel; a second wheel spaced from the first wheel; a support frame that supports the first wheel and the second wheel; a third wheel disposed above the support frame; an endless crawler wound around the first wheel, the second wheel, and the third wheel; and a vehicle-height changing mechanism that changes a position of the support frame in the vertical direction with respect to the third wheel. The vehicle-height changing mechanism has an actuator that is capable of contracting in the vertical direction and that changes the position of the support frame in the vertical direction with respect to the third wheel.

A crawler drive unit relating to one aspect of the present disclosure includes a speed reduction mechanism provided in a running unit for causing a vehicle body to run, where the speed reduction mechanism is configured to transmit a driving force to a crawler provided on the running unit, a transmission mechanism for transmitting the driving force to the speed reduction mechanism, and an electric motor for applying a rotational force to the transmission mechanism. A motor shaft of the electric motor is positioned higher than a rotational axis of an input shaft of the speed reduction mechanism.

A crawler drive unit relating to one aspect of the present disclosure includes a speed reduction mechanism provided in a running unit for causing a vehicle body to run, where the speed reduction mechanism is configured to transmit a driving force to a crawler provided on the running unit, a transmission mechanism for transmitting the driving force to the speed reduction mechanism, and an electric motor for applying a rotational force to the transmission mechanism. A motor shaft of the electric motor is positioned higher than a rotational axis of an input shaft of the speed reduction mechanism.

There is disclosed a track assembly having a frame; an endless track engaged with a track wheel system, the track wheel system having a track driving wheel and at least another wheel. An axle engaging device is rotatably mounted to the frame and is securable to a driven axle of a vehicle. An axis of rotation of the axle engaging device is spaced apart from a ground contacting area of the endless track by a distance taken along an axis perpendicular to the ground contacting area. A mechanism drivingly engages the axle engaging device to the track driving wheel. The mechanism defines a speed ratio defined as a rotational speed of the track driving wheel over a rotational speed of the axle engaging device. The distance is greater than a product of the speed ratio by a radius of the track driving wheel.

There is disclosed a track assembly having a frame; an endless track engaged with a track wheel system, the track wheel system having a track driving wheel and at least another wheel. An axle engaging device is rotatably mounted to the frame and is securable to a driven axle of a vehicle. An axis of rotation of the axle engaging device is spaced apart from a ground contacting area of the endless track by a distance taken along an axis perpendicular to the ground contacting area. A mechanism drivingly engages the axle engaging device to the track driving wheel. The mechanism defines a speed ratio defined as a rotational speed of the track driving wheel over a rotational speed of the axle engaging device. The distance is greater than a product of the speed ratio by a radius of the track driving wheel.

A work machine may include an drive frame, a drivable track coupled to the drive frame, an idler wheel coupled to the drive frame to facilitate movement of the drivable track, and a wheel weight coupleable to the idler wheel. The wheel weight may be coupled to the idler wheel without removing the idler wheel from the drive frame.

A guard assembly is provided for use with a track assembly for a vehicle. The guard assembly includes a guard body having a rigid portion made of a first polymeric material and a flexible portion made of a second polymeric material different from the first polymeric material. The first polymeric material has a greater modulus of elasticity than the second polymeric material. A vehicle including a guard assembly, namely including a guard body is also contemplated.