Types of Pneumatic Actuators
Linear pneumatic actuators are very similar to linear hydraulic actuators in construction but there is a basic difference in their operation. Like the linear hydraulic actuator its counterpart pneumatic actuator is an assembly of piston, cylinder and valves to control the actuator.
Rotary Pneumatic Actuator
Rotary pneumatic actuators converts the energy of pressurized flowing gases into the rotatory motion, similarly as a gas turbine. In this instead of compressed fluid being pressed against the piston walls, the gases flow past the actuator and generates the motion. Rotary Pneumatic actuators are generally fitted with rack and pinion to have high torque output.
Pneumatic gripper is an assembly of pneumatic actuators producing simultaneous motion to give a gripping action. They are used to ensure secure gripping while lifting heavy objects and are fitted with proximity switches to monitor open and closed position of the gripping jaws.
Pneumatic Vacuum Grippers
Vacuum grippers are used lift objects with smooth surfaces which cannot be handled otherwise due to absence of any ends to pick the objects. Vacuum grippers work by creating a low pressure at the actuator end by venturi action generated by pressurized gases moving at fast speed past the nozzle. The actuator end is brought close to the object to be picked, the objects sticks to the end which can be released where required by stopping the gas flow. Advance vacuum grippers can pick multiple objects even with rough surfaces.
Pneumatic Artificial Muscle (PAM)
PAMs work similar to the animal muscles, that is, they contract and expand when given the corresponding signal. Like other pneumatic actuators PAMs are operated by pressurized air. Between the two ends of the PAM there is a balloon type construction, when inflated makes the two ends move closer thus resulting in compression of the PAM. As PAMs can only apply force while contracting, they are used in antagonistic arrangement where the two muscles in the pair can apply force in opposite directions. Spring loaded PAMs can work in single also, they will extend when air pressure is released.
This post is part of the series: Kinematics – Design of Mechanisms
- Kinematics – Design of Mechanisms: Introduction
- Analysis and Synthesis in Machine Design
- Types of Kinematic Joints
- Degrees of Freedom
- Kinematics – Design of Mechanisms: Kinematic Inversion
- Kinematics – Actuation of Machines: Part I – Electrical Actuation
- Kinematics – Actuation of Machines: Part II – Hydraulic Actuation
- Kinematics – Actuation of Machines: Part III – Pneumatic Actuation
- Kinematics – Analysis of Mechanisms: Methods and Techniques
- Kinematics – Synthesis of Mechanisms: Methods and Techniques
- Four Bar Linkages in Machine Design
- Straight Line Mechanisms
- Kinematics – Special Mechanisms: Straight Line Mechanisms – II
- Exact Straight Line Mechanisms