Uncover the World of Cobot Grippers: A Guide to the Various Types Available
Grippers are devices that are attached to the end of a robot's arm and are used to hold, grasp, and manipulate objects. They are a crucial component of robotic systems, as they allow the robot to interact with the environment and perform various tasks. Grippers come in a wide variety of designs, with each design having its own set of advantages and disadvantages. Some of the most popular types of grippers include pneumatic grippers, electric grippers, vacuum grippers, and magnetic grippers. The choice of which type of gripper to use will depend on the specific application and the type of object being grasped.
Understanding the range of grippers available in the market is important to make an informed decision about which one is best suited for your specific application. The different types of grippers have different capabilities and limitations, and it's important to choose one that can effectively handle the objects you need to manipulate. Some grippers are better suited for small, delicate objects, while others are more suitable for large and heavy objects. The environment in which the gripper will be used, such as a clean room or a harsh industrial setting, should also be considered. Additionally, the cost, maintenance requirements and the level of expertise required to operate the gripper should also be taken into account.
Before we get into it, you should know what the main types of cobot grippers.
What are the main types of cobot grippers?
There are several main types of cobot grippers that are commonly used in industry, each with their own specific strengths and best suited for different applications. Some of the main types of cobot grippers include, pneumatic grippers, electric grippers, vacuum grippers and hydraulic grippers.
Now let's get into the different types of cobot grippers:
Hydraulic grippers are a type of gripper that use pressurized fluid, typically oil, to generate the force needed to grasp an object. The fluid is supplied by a pump and is directed to cylinders or actuators located within the gripper. These actuators then generate the force needed to open and close the gripper jaws. Because of the high force density and high power to weight ratio possible with hydraulic systems, they are often used in heavy-duty applications such as metalworking, construction, and material handling.
Hydraulic grippers are known for their high gripping force, durability, and ability to withstand harsh environments. However, they also tend to be larger and heavier than other types of grippers, and require more maintenance and upkeep than other types of grippers.
Vacuum grippers are a type of end effector that uses vacuum suction to grip and manipulate objects. They work by creating a vacuum, or negative pressure, inside the gripper's cups or pads, which then holds the object securely in place.
Vacuum grippers are often used for handling delicate or irregularly-shaped items, as well as for tasks that require a high level of precision and control. They are also often used in applications where the object being handled is porous or has a smooth surface, which can make it difficult for mechanical grippers to grip securely. Vacuum grippers are typically powered by an external vacuum pump and controlled through a vacuum controller, which can be integrated into the robot's control system.
Pneumatic grippers are a type of cobot gripper that uses compressed air to open and close their fingers. They are typically made of aluminum or steel and have a simple, compact design. Pneumatic grippers are often used in applications where the payload is relatively light, and the forces required to grip the object are not high.
They are also relatively inexpensive and easy to install and maintain. Some of the main advantages of pneumatic grippers include their high speed, high accuracy, and low cost. However, one of the main disadvantages is that they are not suitable for heavy payloads and can be less precise than other types of grippers.
Another name for a servo-electric gripper is an electric gripper or an electric actuator gripper. Servo-Electric cobot grippers are a type of cobot gripper that use electric motors and servo drives to open and close their fingers. They are typically more precise and accurate than pneumatic or hydraulic grippers, and can be easily integrated with other automation equipment.
Servo-electric grippers can also be programmed to perform complex tasks, such as pick-and-place operations or part sorting. They are also often used in applications where the payload is relatively heavy, and the forces required to grip the object are high. Some of the main advantages of servo-electric grippers include their high precision, high accuracy, high speed and ability to handle heavy loads. However, one of the main disadvantages of servo-electric grippers is that they can be relatively expensive to purchase and maintain.
Angular / Parallel grippers:
Angular grippers, also known as parallel grippers, are a type of robotic gripper that are designed to grip an object at a fixed angle. They are typically used to grip objects that have a symmetrical shape and require a specific orientation for proper handling.
This type of gripper use two parallel jaws to grip an object, and the jaws move in opposite directions to open and close the gripper. They are often used in manufacturing and assembly applications, such as pick and place, packaging, and material handling. They can be pneumatic, hydraulic or electric and the payload capacity of angular gripper can vary depending on the manufacturer.
Soft grippers are a type of robotic gripper that are designed to handle delicate or fragile objects. They are typically made of soft, flexible materials such as silicone, rubber or soft plastics. They can be used in a variety of applications, such as food handling, electronics, and medical device assembly.
Soft grippers are typically designed to conform to the shape of the object being gripped and can be used in applications where traditional grippers would be too rigid or would cause damage to the object. They can be actuated by pneumatic or electric actuators, and their payload capacity can vary depending on the manufacturer. They have a wide range of applications, from handling fragile products in the food industry, to picking up delicate electronic components in manufacturing.
A magnetic gripper is a type of cobot end effector that utilizes magnetism to grasp and manipulate ferromagnetic objects. It typically consists of one or more permanent magnets that generate a magnetic field to attract and hold ferromagnetic materials, such as iron, nickel, and cobalt. They are commonly used in material handling, assembly, and packaging tasks in industries such as manufacturing, assembly, and packaging.
An adaptive gripper is a type of robotic end effector that can adjust its shape or size to accommodate various types and sizes of objects. This enables the gripper to handle a wide range of objects without the need for manual adjustments or the use of multiple specialized grippers.
Adaptive grippers are useful in industries such as manufacturing, assembly, and packaging, where it is necessary to handle a variety of different objects. They increase the flexibility and efficiency of robotic systems, allowing for the automation of tasks that were previously difficult or impossible to automate.
A jamming gripper, also known as a "jamming finger" or "jamming-based gripper" is a type of adaptive gripper that uses the principles of granular jamming to manipulate objects. It is a relatively new type of gripper that uses a flexible material, such as foam or sand, that can be temporarily solidified by applying air pressure, allowing the gripper to conform to the shape of the object and hold it securely.
Jamming grippers are based on the principle that materials like granules, powders or beads can be compressed to form a solid-like structure when compressed. When the compressed material is released, it returns to its original loose state.
Jamming grippers have the advantage of being lightweight, low-cost, and versatile, as they can be used to handle a wide range of objects of different shapes and sizes. They can be useful in industries such as manufacturing, assembly, packaging, and logistics, where it is necessary to handle a variety of different objects.
A mechanical gripper is a device used to grasp and hold objects using mechanical means, typically using jaws or fingers that close around the object to be held. They are commonly used in industrial robotics and automation systems to handle and manipulate objects in manufacturing or assembly processes.
They can be designed for different types of objects and environments, such as soft or delicate materials, large or heavy objects, or cleanroom environments. They may be actuated using a variety of means such as pneumatic, hydraulic, or electric motors.
When conducting a risk assessment (this is properly explained in the cobot risk assessment article) for a cobot gripper, some key considerations include:
Make sure the gripper meets relevant safety standards, such as ISO 10218-1 and ISO/TS 15066, which cover collaborative robot systems and cobot risk assessment, respectively.
2. Risk of Crushing:
Assess the risk of crushing or pinching between the gripper jaws and other parts of the cobot or surrounding equipment.
3. Risk of Impact:
Assess the risk of impact if the gripper or object it is holding makes contact with a person or other object.
4. Risk of Entanglement:
Assess the risk of entanglement with hair, clothing, or other materials that could get caught in the gripper.
5. Risk of Dropping Objects:
Assess the risk of the object being dropped by the gripper, causing injury or damage.
6. Risk of Electrocution:
Assess the risk of electrocution if the gripper is not properly insulated or if it comes into contact with electrical equipment or power sources.
7. Risk of Fire:
Assess the risk of fire if the gripper is not properly insulated or if it comes into contact with flammable materials.
It's also important to consider the environment and task, for example, if the gripper is used in a hazardous environment, the risk assessment should consider the risks associated with that environment.
It's recommended to consult a professional risk assessor to ensure that all potential hazards have been identified and appropriate measures have been taken to mitigate them.
There are many types of cobot grippers available, each with its own set of advantages and disadvantages. When choosing a gripper, it is important to consider the object type and size, actuation type, safety, compatibility, payload and reach, speed and precision, ease of use, and additional functionality (this is explained in another article "How to Choose the Right Collaborative Robot Gripper?").
For cobot grippers, it is also important to conduct a thorough risk assessment to ensure the safety of both the cobot and human operators. It is recommended to consult a professional risk assessor to ensure that all potential hazards have been identified and appropriate measures have been taken to mitigate them.
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