Wheeled Robot Chassis: What Are The “Wear Parts”?

With the continuous development and innovation of the robot industry, the performance and lifespan of robot components have significantly improved. However, due to its structural characteristics and the various stresses and wear that the robot chassis has suffered from long-term operation in complex environments, its driving system, sensing and positioning system, walking and supporting components have different degrees of wear.

XspireBot, as an integrated robot chassis supplier specializing in R&D and manufacturing, offers main products including Ackermann chassis, differential chassis, four-wheel drive robot chassis, and tracked chassis. Drawing on our extensive experience and practical knowledge, we will help you understand the wear-prone components of wheeled robots to better utilize them and extend their service life.

Mobility and Support Components

1. Tires/Wheel Surfaces  

As a component in which the entire robot contacts the ground, the tire bears all the weight and driving force. The tire susceptibility of wheeled robot chassis is mainly due to the complexity of the working environment and the tire's structural characteristics.

Firstly, during operations, robots frequently perform sudden stops, starts, and on-the-spot turns, causing intense friction between the tires and the ground, which can lead to tread wear.

Second, the tires may be punctured by sand, stones, or glass fragments when the robot is in motion.

In addition, tires, as rubber products, will age and crack during long-term compression, deformation, and repeated stress. Coupled with factors such as ultraviolet irradiation in the environment, chemical corrosion, and temperature changes, the degradation of rubber materials will accelerate.

2. Hub Bearings

The hub bearings of wheeled robot chassis are prone to damage primarily due to their harsh operating environment and complex load conditions:

In outdoor or industrial environments, the bearing sealing system is susceptible to contamination from dust, moisture, and chemical pollutants, leading to lubrication failure and corrosion of metal surfaces.

Secondly, due to poor sealing or prolonged use, lubricant may gradually leak or become contaminated, resulting in increased internal friction, overheating, and wear.

In addition, frequent start and stop and speed changes cause the bearing to bear periodic stress, which is prone to fatigue peeling; vibration and impact will damage the oil film inside the bearing and aggravate the wear process. These factors often interact to form a vicious cycle, making hub bearings one of the most critical consumable parts in wheeled robot chassis that require regular inspection and replacement.

Drive System

1. Motor

During robot movement, the motor plays a crucial role in driving the robot, enabling it to accurately perform various motion tasks. The motors in wheeled robot chassis are prone to damage primarily due to the complexity of their operating environment and the stringent nature of their load characteristics.

Secondly, the chassis space is compact, and high dynamic movement allows heat to accumulate rapidly. Taking the servo motor as an example, poor ventilation or failure of the cooling system will cause the coil to overheat and accelerate insulation aging. At the same time, lubricating oil is prone to deterioration under long-term high loads, aggravating the friction of parts. ‌

In addition, in outdoor or industrial environments, it is also necessary to face erosion by harsh conditions such as dust, moisture, and temperature changes. These factors collectively cause motor winding insulation aging, accelerated bearing wear, and reduced heat dissipation performance, ultimately leading to overheating, efficiency reduction, or even motor failure. Therefore, the motor is one of the most critical components requiring focused maintenance and monitoring in the chassis of wheeled robots.

2. Reducer

The reducer in the robot chassis is primarily responsible for converting the high-speed rotation generated by the motor into corresponding low-speed and high-torque rotation, enabling the robot to move more smoothly and precisely. However, the service life of the reducer is often affected by factors such as the operating environment and workload.

First, reducers are subjected to high rotational speeds and large torques from the motor over extended periods, while also enduring impact loads generated during robot startup, braking, and hill climbing, causing gears and bearings to experience alternating stresses and resulting in fatigue wear.

Second, reducers on the chassis are exposed to harsh environments such as dust and humidity, which can lead to lubricant degradation or contamination, accelerating friction and wear on bearings and gears.

Additionally, the frequent forward and reverse operations and precise position control requirements of robots subject the reducer to complex load changes, easily causing increased gear clearance and reduced transmission accuracy.

Since the internal gear meshing precision of the reducer is extremely high, even minor wear can affect transmission efficiency and positioning accuracy, making it a critical component with a relatively high failure rate in the chassis system.

Sensing and Positioning System

1. Encoder

Robots require precise feedback and sensory information to perform various flexible tasks, which rely on encoders for real-time monitoring and identification. The encoder of the wheeled robot chassis is vulnerable to damage mainly due to the complexity of its working environment and the precision characteristics of the sensor itself.

First, the encoder is installed on a moving chassis and is directly exposed to harsh environments such as dust, moisture, oil, and other harsh conditions. At the same time, it is necessary to withstand the weight of the robot, impact vibration during movement, and bumps caused by uneven ground. This continuous mechanical force can easily lead to loosening of the encoder's internal components, shedding of solder joints, or unstable signal transmission.

Second, instantaneous current surges caused by operations like starting and stopping, thermal expansion and contraction at different operating temperatures, and complex electromagnetic interference environments all accelerate encoder aging.

Additionally, since sensors are highly sensitive to environmental conditions as precision electronic components, and wheeled robots must operate in dynamic, ever-changing field environments, this contradiction makes encoders the most vulnerable components in the entire chassis system. Their reliability must be ensured through protective design, regular calibration, and timely replacement.

In summary, due to the varying application scenarios of robot chassis and the influence of factors such as operating environment and workload, the wear-prone components of the robot chassis directly impact its service life. Therefore, understanding the precautions for robot chassis and conducting regular maintenance and upkeep are of critical importance.

(1) The operating temperature range is -20°C to 50°C; do not use in environments below -20°C or above 50°C;

(2) During use, ensure that the tire pressure of the robot tires remains consistent. If a tire leaks or other issues occur, promptly maintain or replace the tires.

(3) Strictly adhere to the motor's rated power. Regularly inspect the wear condition of the motor bearings and gears. If abnormal vibrations or noises occur, immediately shut down the system for inspection to prevent further damage.

(4) Before the first use of the reducer, add an appropriate amount of lubricating oil. The first replacement should be done after 300-400 hours of operation, and subsequent replacements should be done every 1500-2000 hours. In high-temperature or dusty environments, the inspection cycle should be shortened.

(5) Regularly wipe the sensor surface with a soft cloth to remove dust and debris. If any damage or abnormalities are found in the cables, they should be replaced or repaired promptly.