Mechanical Components of Industrial Robots
In general, the main components of an industrial robot consist of the controller, robot body, robotic arm, sensors, and the end-effector. All of these components have their own role and are important to the overall operation of an industrial robot. However, behind the robot exterior are the mechanical parts which are just as important. The mechanical components of an industrial robot allow it to move and function to be able to complete various manufacturing applications. For instance, the mechanical components of the FANUC M-410ib/160 give it the ability to move its arm up and down for automated palletizing applications. There are four main mechanical components of industrial robots; actuators, reduction gears, encoders, and the transmission.
- • Actuator - An actuator is the motor of an industrial robot and is sometimes referred to as the drive. Actuators are responsible for creating specific motions and controlling the movements of the articulated robot. Robots typically have multiple actuators and they correspond with the number of axes a robot has. For instance, the FANUC M20ia has six axes, therefore it will have six actuators. Each actuator functions as the joint of a robot, controlling a specific robotic movement. For example, the actuator located in the third axis of the Yaskawa 1440 controls the vertical movement of its arm. Servo motors are the most common actuators used in industrial robots since they have advanced functionality which allows for extreme precision. Robotic actuators are usually powered electrically but may also be either hydraulic or pneumatically powered.
- • Reduction Gear - One of the benefits of industrial robots is their incredible power, which allows them to lift heavy payloads or operate at fast speeds. Robotic actuators are used to generate this power with their movements, however, they are limited to how much they themselves can produce. Reduction gears are used to increase the power of each actuator. The combination of reduction gears and actuators produces the high power needed for industrial robot operation. Each actuator will have its own reduction gear. Since the four-axis Motoman EPL160 has four actuators, it will only need four reduction gears.
- • Encoder - Encoders are used to provide data about a robot’s movement, such as how far it has traveled or what direction it moved. This data is critical to allowing the motors to control the speed and position of a robot. Encoders enable greater precision and accuracy in the operation of an industrial robot. They are integrated with each actuator of a robot. They typically consist of a disk with fixed slits at recurring intervals. This disk is attached to the rotating base of an actuator. Light will either transmit through the slits or be blocked which signals the rotation and speed of an actuator. Six axis robots like the FANUC Arcmate 120ic have 6 encoders.
- • Transmission - The transmission is the component responsible for transmitting the power generated between the reduction gears and the actuators. It takes the power created by the reduction gear and transfers it to the actuator, allowing the motor to increase its power output. A transmission can also change the angle and intensity of power.