A tracked AGV undercarriage mainly consists of rubber or metal tracks, drive sprockets, track rollers, idlers, carrier rollers, a track tensioning mechanism, and track frames. Some designs also integrate the travel motor and gearbox into the track drive assembly.
These components work together to support the vehicle, transmit driving power, guide the tracks, and maintain proper track tension. Unlike a conventional wheeled undercarriage, a tracked system distributes the vehicle's weight over a larger ground contact area through continuous tracks. The actual configuration should be selected according to the AGV's payload, travel speed, ground conditions, and operating environment.
1. Main components of a tracked AGV undercarriage
1. Track
The track is the main ground-contact component of a tracked AGV. It supports the vehicle weight and transfers the traction force generated by the drive system to the ground. Its width, length, material, and structural design affect ground contact pressure, traction, and operating stability.
Tracks are commonly classified into rubber tracks and metal tracks according to their materials and construction.
Rubber tracks have a degree of elasticity and generally produce less impact on the ground during operation. They are suitable for applications where floor protection and noise control are required. Some rubber tracks also contain reinforcing steel cords or metal cores to improve tensile strength and provide a more reliable engagement structure for power transmission.
Metal tracks generally consist of track links and track shoes. They have high structural strength and are used in applications that require greater impact resistance and mechanical durability.
Track selection should account for floor material, operating load, turning frequency, and working conditions. The material alone is not enough to determine whether a particular track is suitable for an application.
2. Drive sprocket
The drive sprocket is the main power transmission component in a tracked undercarriage. It is usually connected to the output shaft of the travel gearbox. Motor power passes through the reduction mechanism to the drive sprocket. The sprocket teeth then engage with the track links, drive lugs, or corresponding engagement features to move the track continuously.
The tooth profile, pitch, outer diameter, and mounting dimensions of the drive sprocket must match the track design. An incorrect tooth profile or excessive engagement clearance may cause transmission impact, abnormal wear, or tooth skipping.
When designing and machining a drive sprocket, its tooth profile and mating dimensions must be determined according to the specific track structure. Material strength and wear resistance also need to be considered.
3. Track rollers
Track rollers are installed along the lower part of the track frame. They support the weight of the AGV and its payload, transferring the load to the track.
During vehicle operation, the track rollers move along the inner load-bearing surface of the track, helping maintain stable movement of the lower track section. Their number, diameter, and mounting positions depend on the vehicle weight, undercarriage length, and load distribution.
Track rollers are generally manufactured from wear-resistant metal materials. Some designs also include bearings and sealing components to maintain smooth rotation and reduce the effects of dust and debris on internal parts.
If a track roller becomes worn, its bearing becomes seized, or its mounting position is incorrect, running resistance may increase. Uneven loading and abnormal track wear may also occur.
4. Idler
The idler is usually installed at one end of the track frame. Together with the drive sprocket at the other end, it defines the track's running path. Its main function is to guide the track around the front or rear of the undercarriage and maintain proper alignment during operation, reducing the risk of track misalignment or derailment.
The idler is generally mounted on the undercarriage through bearings and a support structure. Its profile and guiding features must match the inner structure of the track.
In many tracked undercarriage designs, the idler is also connected to the track tensioning mechanism. Moving the idler changes the track tension. However, guiding and tensioning are separate functions, and their mechanical arrangement depends on the undercarriage design.
5. Carrier rollers
Carrier rollers are generally installed on the upper part of the track frame. They support the upper return section of the track and prevent excessive sagging caused by the track's own weight.
On undercarriages with longer tracks or larger unsupported spans, carrier rollers help maintain the track's position and reduce unwanted contact between the track and the frame.
Their number and mounting positions depend on track length, structural design, and operating requirements. Some AGV undercarriages with short tracks or compact layouts do not require separate carrier rollers.
6. Track tensioning mechanism
The track tensioning mechanism adjusts and maintains the required track tension. It is commonly integrated with the idler mounting arrangement.
Common designs include screw-type, spring-loaded, and hydraulic tensioning mechanisms. By adjusting the tensioning mechanism, the position of the idler can be changed to control track tension.
If the track is too loose, it may skip teeth, become misaligned, or derail. Excessive tension increases the operating loads on the drive sprocket, track rollers, bearings, and track itself, accelerating wear.
The tensioning mechanism therefore needs an appropriate adjustment range and a reliable locking arrangement. Actual track tension should follow the track manufacturer's specifications. Increasing tension alone is not an appropriate solution to recurring track loosening.
7. Track frame
The track frame is the main supporting structure of the tracked undercarriage. It provides mounting points for the drive sprocket, idler, track rollers, carrier rollers, and tensioning mechanism.
The frame must have sufficient strength and rigidity to withstand the vehicle weight, payload, and impact loads generated during operation.
It also maintains the relative positions and alignment of the drive sprocket, idler, and track rollers. Frame deformation or inaccurate mounting hole positions may cause track misalignment, localized wear, and transmission problems.
For non-standard AGV undercarriages, the dimensions, mounting holes, and bearing housing arrangements of the track frame often need to be adapted to the overall vehicle design. We can manufacture support plates, connecting brackets, shaft components, and other metal structural parts through CNC precision machining according to customer-supplied engineering drawings.
2. Power transmission in a tracked AGV undercarriage
The travel system of a tracked AGV operates through the coordinated action of the motor, gearbox, drive sprocket, and track.
When the control system sends a command to the travel motor, the motor starts rotating. Its output torque passes through the gearbox to the drive sprocket. The sprocket engages with the track and drives it through a continuous cycle. As the track contacts the ground, it generates traction force that moves the AGV forward or backward.
During operation, the track rollers support the vehicle weight and guide the lower section of the track. The idler maintains track alignment, while the carrier rollers support the upper return section. The tensioning mechanism adjusts the idler position to maintain the required track tension.
When the AGV needs to turn, the control system generally adjusts the speed of the tracks on the left and right sides. When both tracks move at the same speed, the vehicle travels in a straight line. A speed difference between the two tracks produces a turning motion. When both tracks move in opposite directions at equal speeds, the vehicle can rotate in place, provided the undercarriage design and ground conditions allow this movement.
3. Component selection and machining for tracked AGV undercarriages
The operating stability of a tracked AGV depends not only on the tracks themselves but also on the dimensional compatibility and mounting accuracy of the drive sprocket, track rollers, idler, and tensioning mechanism.
During component selection, the vehicle weight, maximum payload, travel speed, and ground conditions should be considered when determining track material and specifications. The engagement dimensions of the drive sprocket, load capacity of the track rollers, and adjustment range of the tensioning mechanism also need to be checked.
For non-standard tracked AGVs, some metal structural components must be manufactured according to the vehicle layout. These include track drive mounting bases, support frames, bearing housings, connecting shafts, and tensioning mechanism brackets. Their dimensions and mating requirements should be defined by the customer's engineering drawings.
Hansheng Automation provides CNC precision machining services for metal structural components according to customer-supplied drawings. We manufacture custom parts for tracked AGVs and other automation equipment. Our machining capabilities also cover precision yacht components, RC racing car structural parts, tobacco packaging machinery components, and filling machinery parts. Each component is manufactured according to its specified dimensions and assembly requirements.
