The wheel is the most common moving element among other possibilities including legs, flying, swimming and rolling. A wheel provides at least speed, accuracy and stability for a robot, three characteristics very important in designing and build robots. Finding inspiration in everything, the researchers design many types of wheels including standard, orientable, ball, and omnidirectional wheels.
Depending on the design and requirements, standard wheels are used especially for classical methods of driving and steering while orientable and ball wheels are included in the same category and user for balancing a robot. Omnidirectional wheels are very good for driving and steering and are used when the robot should have the ability to move in all directions.
In this article, I made an overview for standard, orientable, ball, and multi-directional wheels.
Most common wheels used in robotics is standard wheels. This type of wheels is characterized by two degrees of freedom and can run in front and back. The angle between the robot frame and the wheel is constant while the center of the wheel is fixed to the robot frame.
In this section of the article I made an overview of standard wheels designed to be used in robotic projects.
Based on two types including center and off-centered oriented, orientable wheels are standard wheels mounted to a fixed or omni-directional fork designed to catch the wheel. Compared with standard wheels, these wheels are used in robotic projects for balance and less or not at all to drive a robot.
Below is a list with orientable wheels ready for use in robotic projects.
Based on a ball, these wheels have a total freedom of 360 degrees and like orientable wheels are used to balance a robot. The ball can be builded from metal or plastic and is positioned on the frame with a holder. Bellow I made an overview of ball wheels for robots.
Small wheels are attached on a large wheel to build a multi-directional system designed for robots for movement in any direction. This type of wheel is used for both drive and steer a robot. One important advantage using multi-directional wheels is a low resistance when the robot is moving in any direction. The smaller wheels are attached to a large wheel at 45 degrees.
Below you can be found links to a comprehensive list with multi-directional wheels.