Hydraulic Gripper Essay

1. Background
1.1 Introduction
The progress of science and the advent of technology in the last few centuries have given birth to innovation and have enabled us to develop and use newer, sophisticated machinery in our everyday lives. One such ingenious example of this is a gripper. Grippers are devices used with systems involving robots and are used to pick up or place an object on automated systems such as an assembly line or a conveyor belt. The ‘finger’ part of the gripper ‘arm’ consists of jaws, which aid in gripping or holding an object. They come in a variety of styles and powered designs. Three common types are parallel, three-finger, and angled designs. The most common are parallel designs, with two fingers that close on a workpiece

Three-finger designs hold the workpiece in the center, and have three fingers offset by 120°. Finally, angled designs feature jaws that work at a variety of different angle openings (for example, 30°, 40°, etc.). In addition, three choices of power are available: the most common being pneumatic grippers, electromechanical grippers, and hydraulic grippers. Hydraulic grippers are most often used in conjunction with a piece of equipment that only has a hydraulic power source for actuators, and is the least common type of gripper in use. Most hydraulic grippers are designed for a hydraulic system where the cylinder diameter is made with less surface area, meaning that a hydraulic gripper would have the same force at 60 bar as a pneumatic gripper of the same size at 6 bar. In general, hydraulic and pneumatic grippers have the same basic actuation principle. They include direct acting piston designs

This type of robot gripper uses a rubber or polyurethane suction cup to pick up items. Some vacuum grippers use a closed-cell foam rubber layer, rather than suction cups, to complete the application. Pneumatic Grippers The pneumatic gripper is popular due to its compact size and light weight. It can easily be incorporated into tight spaces, which can be helpful in the manufacturing industry. Pneumatic robot grippers can either be opened or closed, earning them the nickname “bang bang” actuators, because of the noise created when the metal-on-metal gripper operates. Hydraulic Grippers The hydraulic gripper provides the most strength and is often used for applications that require significant amounts of force. These robotic grippers generate their strength from pumps that can provide up to 2000psi. Although they are strong, hydraulic grippers are messier than other grippers due to