Robotic Drives, Hardware, and Components 220

This class describes the physical components of industrial robots. It also describes how these devices move and cause motion to perform work.

Class Details

Class Name:
Robotic Drives, Hardware, and Components 220
Number of Lessons:
Additional Language:

Class Outline

  • Objectives
  • Industrial Robots
  • Robot Hardware
  • Frame Materials
  • Robot Joints
  • Bearings
  • Hydraulic Drives
  • Pneumatic and Electric Drives
  • Servomotors
  • Transmissions
  • Ballscrews
  • Sensors
  • Wiring and Hoses
  • Summary


  • Describe industrial robots.
  • Identify common robot hardware.
  • Describe robot frame materials.
  • Describe robot joints.
  • Describe robot bearings.
  • Describe hydraulic drives.
  • Describe pneumatic and electric drives.
  • Describe servomotors.
  • Describe robot transmissions.
  • Describe how robots use ballscrews.
  • Describe sensors for robots.
  • Describe the wiring and hoses used for robots.

Job Roles



Vocabulary Term Definition
actuator A component such as a cylinder, motor, or rotary device that directly helps convert fluid or electrical energy into mechanical energy.
articulated robot A type of robotic arm that closely resembles a human arm. The arm of an articulated robot has revolute joints and the number of joints can vary.
automatic guided vehicle An industrial robot that can move freely about the workspace. AGVs can take the form of carts, forklifts, or tow vehicles.
backlash The relative movement of interlocked mechanical components that occurs when motion is reversed. Backlash is a form of mechanical inefficiency that should be minimized.
ball bearing A rolling-element bearing containing metal balls placed between two parts. A ball bearing allows machine parts to move with little friction.
ballscrew A long, threaded device that rotates to provide robots precise linear motion control. The ballscrew is powered by a servomotor.
base plate A precisely ground plate that acts as the foundation of the robot. Various components, such as the robot base or arm, are fastened to the base plate.
bearing A friction-reducing device that allows one moving part to glide past another moving part without excess wear or friction.
carbon fiber A carbon-based composite material that is very strong given its light weight. Some specialized robot frames are constructed from carbon fiber.
Cartesian robot A type of robotic arm that has prismatic joints only. The linear movement of the joints gives the Cartesian robot a highly rigid structure that allows it to lift heavy objects.
clean room A room in which temperature, humidity, and air pressure are controlled and maintained at a specific level. Sensitive components require an environment with minimal contamination.
compressor A component that pressurizes ambient air and directs it into a pneumatic system.
contact sensor A type of sensor that detects physical contact with an object or surface. Contact sensors for robots include tactile, force, and collision sensors.
controller The main device that processes information and carries out instructions in a robot. Also known as the CPU, or processor.
count An increment on an encoder that measures the distance a robotic arm has traveled.
crossed roller bearing A common type of robot bearing that is able to withstand and support high axial loads.
cylindrical robot A type of robotic arm that has a combination of revolute and prismatic joints. Cylindrical robots work well in round workspaces.
degrees of freedom The available ways a component can move in three-dimensional space. Robots typically have three to six degrees of freedom.
drive Any device that introduces motion into a system. Electric motors, especially servos, are the most common robot drive.
electric drive An actuator that uses electricity to create mechanical motion.
electrical noise A power line disturbance caused by sudden changes in the load. Electrical noise is problematic to robot communications equipment because they cannot always differentiate between an intended electrical pulse and an unintended electrical spike.
encoder A measuring device for motion control that is divided into a fixed number of increments called counts. In a typical encoder, one revolution equals one million counts.
end-effector The end component of a robotic arm that is shaped like a hand or like a specialized tool. Also known as an end-of-arm tool (EOAT).
force multiplication The exponential increase in available power. Hydraulic drives and pneumatic drives provide high force multiplication.
frame The physical body of a robot, such as the base, arm, and wrist. Robot frames are typically composed of steel, iron, or aluminum.
friction A force that resists motion between two objects that are in contact with each other.
gear reduction A gear ratio used to decrease the speed and increase the torque of mechanical energy, or rarely, vice versa. A 1:2 gear ratio is an example of a gear reduction.
gear train A set of gears arranged to transfer mechanical energy from one part of a mechanical system to another.
ground A wire that connects an object to the earth that helps prevent the build up of electric charges. All robots should be grounded.
hardware Any physical and mechanical component of a robot. Examples of hardware include the frame, joints, drive system, and sensors.
hydraulic drive An actuator that uses pumps, valves, and pressurized liquids to create mechanical motion.
hydraulic pump A mechanical device used to move liquids. The hydraulic pump introduces pressure into the system.
industrial robot A programmable mechanical device that is used in place of a person to perform dangerous or repetitive tasks with a high degree of accuracy.
inertia The tendency of an object to stay in its state of rest or motion until acted on by an external force. Torque and braking must overcome inertia to accelerate or decelerate a motor.
joint The location at which two or more parts of a robotic arm make contact. Joints allow parts to move in different directions.
limit switch A type of mechanical sensor that requires physical contact to detect the presence or absence of an object. Limit switches are one of the original types of sensors.
mechanical advantage The difference between the applied force and the work accomplished. Mechanical advantage allows machines to perform more work with less effort.
moment load Load such that when applied to a bearing system, tends to overturn or bend the axis of rotation in an angular direction.
noncontact sensor A type of sensor that detects changes in light or an electromagnetic field. Noncontact sensors for robots include proximity sensors and vision sensors such as photoelectric sensors and cameras.
payload The maximum load that a robot can manipulate.
photoelectric sensor A type of sensor that detects the presence of an object through the use of a beam of light. Photoelectric sensors have an extremely broad sensing range, from a few millimeters to 100 feet away.
pneumatic drive An actuator that uses pressurized air to create mechanical motion.
prime mover A device supplying the force necessary to turn the shaft of a generator or alternator. Hydraulic drives and pneumatic drives require prime movers.
radial load Force that is applied perpendicular to the axis of a bearing's shaft. Radial loads are also called rotary loads.
sensor A device that detects the presence or absence of an object, or certain properties of that object, and provides feedback. Robots use sensors to interact with their environment.
servomotor A type of motor used in applications that require precise positioning. Many robots use DC servomotors.
shielded An outer layer of insulation covering an inner layer of conducting material. Shielded cable is used to reduce electronic noise and protect against mechanical damage.
tapered roller bearing A type of roller bearing featuring tapered inner and outer ring raceways and rollers. The tapered roller bearing can withstand high radial and thrust loads.
thrust load Force that is applied parallel to the bearing's axis. Thrust loads are also called axial or linear loads.
titanium A silvery white metal that has a high strength-to-weight ratio and corrosion resistance. Titanium is often used in clean room applications.
transmission A machine assembly that uses a combination of gears and other mechanical components to change the speed or torque of mechanical energy.
zero backlash A type of gear system that maintains a constant clamping force, thus eliminating almost all effects of backlash.