Considering a new robotic arm for your business but overwhelmed by the options available?
This article will cover everything you need to know about hydraulic robotic arms, the heavy-duty, high-payload solution. Unlike electronic robotic arms, hydraulic robotic arms utilize hydraulic power to perform their tasks effectively.
What is a Hydraulic Robot Arm?
Hydraulic robot arms are powered by pressurized hydraulic fluid, which provides the force needed to lift, move, and manipulate heavy loads with precision. These versatile arms typically feature multiple joints, similar to a human arm, powered by robust cylinders and actuators.
Hydraulic systems use pressurized fluid to generate force and motion, making them ideal for high-power applications such as manufacturing. Each joint of a hydraulic robot arm is equipped with hydraulic cylinders. When fluid is pumped into these cylinders, they extend, causing the arm to move. By controlling the fluid flow, the speed, direction, and precision of the movement can be regulated with remarkable accuracy.
The high power density of hydraulic systems allows these robot arms to lift and move very heavy loads, often weighing several hundred kilograms. This capability makes them suitable for demanding applications, like automotive manufacturing, where heavy components need to be handled frequently. Additionally, hydraulic arms are highly rigid, enabling them to lift substantial weights while maintaining a great degree of precision.
How do Hydraulic Robot Arms Work?
Fluid:
Hydraulic robot arms get their power from pistons and Hydraulic fluid.
The pistons move back and forth, powered by the hydraulic fluid under high pressure; as the pistons move, they actuate the joints of the robotic arm, allowing it to bend, extend, and rotate.
By controlling the pistons with a computer, the arm can be precisely positioned and moved.
Power and Torque in Hydraulic Robot Arms
Power:
The power of a hydraulic system comes from an electric pump that pressurizes the fluid, usually oil, and pumps it through hoses to the pistons. Solenoid valves regulate the fluid flow to each piston, enabling independent movement. Additionally, sensors provide feedback to a computer, allowing it to monitor the position and speed of each joint.
Torque:
Hydraulics generate a significant amount of torque, enabling hydraulic arms to lift very heavy loads—some can even lift several tons! This high torque also allows for quick acceleration and deceleration, making them suitable for high-speed precision tasks. However, hydraulic arms typically exhibit lower repeatability compared to electric servomotors and require more maintenance to keep the hydraulic system functioning properly.
Key Applications of Hydraulic Robot Arms
Hydraulic robotic arms are widely utilized in heavy industries, particularly automotive manufacturing, due to their powerful actuators, which excel at lifting and manipulating heavy components. Here are three key industries that effectively use these arms:
Automotive Industry:
In automotive plants, hydraulic robots are crucial for tasks such as moving vehicle frames, installing heavy components like engines and transmissions, and handling large parts like doors, hoods, and axles. Their high power and precision enable smooth lifting and maneuvering of even the heaviest auto parts during assembly.
Heavy Machining:
Hydraulic robot arms are commonly found in heavy machining applications, such as metal fabrication, where they lift, position, and weld large metal components. Their robust hydraulic actuators can endure the high heat and forces involved in welding thick steel parts, and they are also effective for moving raw materials, workpieces, and finished parts throughout a machining facility.
Packing and Palletizing:
Hydraulic robotic arms are ideal for efficiently moving and stacking boxes, crates, and pallets. Their high lifting capacity and range of motion allow for rapid picking, rotating, and placing of heavy loads. In packaging facilities, hydraulic arms can quickly grab empty containers, fill them, seal them, and stack them at impressive speeds.
Disadvantages and Limitations of Hydraulic Robot Arms
While hydraulic robot arms offer many advantages, there are some downsides to consider before making an investment:
Higher Maintenance Requirements:
Hydraulic systems require frequent maintenance, including replacing hydraulic fluid and inspecting components such as pumps, valves, cylinders, and hoses for wear or damage. Over time, hydraulic fluid can degrade, losing its lubricating properties due to heat. Additionally, hoses and seals naturally age and may need replacement, leading to higher costs and increased downtime.
Risk of Oil Spills and Leaks:
There is always a risk of hydraulic fluid spills, leaks, or drips, which can be hazardous and damaging. Close monitoring and regular inspections are essential to minimize these risks. Any spills or leaks must be cleaned up properly, and contaminated materials must be disposed of according to regulations.
Limited Precision:
Although hydraulic robot arms are powerful, they generally lack the precision of electric robot arms. The bulkiness of hydraulic components and the compressibility of hydraulic fluid limit the accuracy with which forces and movements can be controlled. Consequently, for applications that demand high precision, electric robot arms are often the better choice.
Slower Movements:
Hydraulic robot arms typically move more slowly than electric ones due to the nature of hydraulic systems. The time it takes for hydraulic fluid to flow through the system and the inertia of hydraulic components result in slower acceleration and less dynamic responses. Additionally, the speed and cycle times may be restricted by the actuation rate of hydraulic valves and cylinders.
Environmental Impact:
Hydraulic robot arms raise environmental concerns related to the manufacturing, transport, use, and disposal of hydraulic fluids, which are often petroleum-based. This poses a risk of accidental spills and leaks that can release these oils into the environment. Many regions have regulations that limit or prohibit the use of certain hydraulic fluids. However, the situation is improving with the introduction of alternative "green" fluids and better containment systems that can mitigate some of these environmental impacts.
Summing Up
Hydraulic robot arms are powerful and versatile tools that have huge benefits for the manufacturing sector.
While the initial investment can seem high, the long-term benefits in efficiency and productivity are well worth it – especially for bigger companies that need to work with high payloads.
