Comparison of Standard Hydraulic Cylinder and Special Hydraulic Cylinder
Comparison of Standard Hydraulic Cylinder and Special Hydraulic Cylinder
Comparison of Standard Hydraulic Cylinder and Special Hydraulic Cylinder
Hydraulic cylinders are the power behind many industrial and mobile operations. Compared to other actuators, hydraulics provide:
Efficient power-to-weight ratios.
Variable speed control.
Mounting and positioning advantages.
Cost and energy efficient designs.
But when a design team opts for hydraulic actuators, it faces another decision: Go for commercial off-the-shelf (CETOP) cylinders or have them custom-made.
Standard Hydraulic Cylinder Manufacturing
CETOP cylinders have definite advantages.
For example:
They are easily available and can be delivered immediately.
They minimize production costs.
Their performance is proven.
They are cheaper than custom-made versions.
The main problem with standard cylinders is that they are not optimized for any particular design team's application or product. In fact, it is likely that the CETOP cylinders were either overdesigned or underdesigned. If they are over-designed, customers will pay for performance and features they never use. This can lead to inefficiencies, loss of performance, and downtime. All this leaves customers dissatisfied.
Poorly designed CETOP cylinders are even worse. Users are faced with underperforming cylinders that are likely to fail, leading to costly repairs and replacements. Depending on failure it can be extremely dangerous.
Special Hydraulic Cylinders Manufacturing
For many products and equipment, engineers must choose special cylinders. It allows engineers to "build" cylinders to suit customers' needs and eliminates inefficiencies caused by under- or over-engineering.
They also provide many benefits.
Design teams can move ports to different locations, change the mounting style, adjust the orientation, and make other improvements. Even if no major design changes are required, custom cylinders can be modified to ensure an exact fit and simplify installation. For example, ports, manifolds and hoses are all lined up, avoiding delays and risky “good enough” installation.
A ready-to-use roller is a one-size-fits-all solution. Therefore, instead of designing products to fit into the cylinder, engineers can design them to accommodate the cylinder. This limits design flexibility and teams struggle to balance space, weight, performance, serviceability, and ease of installation.
Companies are also turning to specialty cylinders to meet ISO certifications or other industry standards and regulations. This is especially important in medical, food and beverage, and other highly regulated industries. Engineers can also design custom cylinders that are more compact and lightweight than their CETOP counterparts, making custom hydraulics better for tight spaces and mobile use.
There are several important design elements to keep in mind when specifying custom cylinders. Each of these issues poses a challenge for standard cylinders, but custom designs can overcome these challenges and turn them into opportunities for better cylinder performance. Points to consider include:
Cylinder sizing. An improperly sized cylinder can have serious effects on the performance, efficiency and reliability of any hydraulic system. The size of the cylinder bore is particularly important as it determines the force the actuator can produce. If the cylinder diameter is too small, the actuator may not achieve the customer's target speeds or cycle times.
Rod selection. Its diameter and type of material are important when choosing the best rod for a roller. The goal is to get the lowest priced bar suitable for the current application. Engineers can design better, more efficient rods by designing special rollers that consider fatigue, buckling and impact failure. This can help reduce the rod diameter, resulting in a reduction in the weight of the cylinder and the price of the cylinder.
Custom rollers and rods also allow designers to choose from a variety of materials. For example, the nitro steel shaft system provides protection in applications where there is constant exposure to chemicals such as fertilizers. When it comes to handling debris that could affect the shaft and lead to premature failure, induction hardened shafts can be used for additional protection that exceeds that of standard chrome.
Seals. No gasket material or type is compatible with every cylinder design. Depending on the customer's application, they can be made from elastomers, thermoplastics, or thermoplastic elastomers such as rubber, polyurethane, and polytetrafluoroethylene. To obtain the correct custom seal, the application and its pressure, temperature, speed and environment must be considered.
Cylinder assembly, installation and maintenance. Specialty cylinders with routing ports, manifolds, and hoses/fittings designed with a specific application in mind can simplify assembly and installation. This saves time when installing the cylinder at the customer's location. It also simplifies operations by making the cylinder more accessible for repair and maintenance.
In addition to being lighter and more compact, custom cylinders are often easier to assemble because bearings and pinholes can be added wherever they are needed. Changes in mounting location, even seemingly minor, can significantly increase cylinder performance, efficiency and product life. And installations won't take nearly as long.
If a company must spend time and money on tedious installations and purchase additional fittings or longer hoses, the less expensive CETOP cylinders quickly become the more expensive option. There is also the risk of dissatisfying customers.
CETOP rollers will struggle with most of the above issues and will probably never be better than "good enough". But custom hydraulic cylinders can use these design features and application constraints as a blueprint for success. The resulting cylinders will be much closer to optimum. For example, piston rods can be customized to the exact length and diameter required and made from materials best suited to the application.
Special cylinders also offer better design integration. Valves, valve manifolds and electronics can be placed directly into the cylinder body. This helps customers get their equipment up and running quickly.
Special cylinders can also be designed for specific operating conditions and environments. It does not matter if the cylinders are exposed to high ambient pressures in deep-sea environments, high ambient temperatures close to sweltering furnaces, or sub-arctic conditions; special rollers can handle this.
Rescue Special Hydraulic Cylinders
Custom cylinders can solve challenging design problems and lead to more elegant and workable solutions. For example, a company was wasting a lot of time and money trying to remove all the air from the cylinders of a machine it was building. To further complicate the problem, the standard cylinders they used had to be recessed into the frame. They switched to a special cylinder with a piston rephase valve that can push all the air out from the inside. This has enabled customers to save significant installation time.
In another example, a company's design team had little space to work with, so they chose the standard cylinder to fit into the space. After installing it, the designers realized they could not attach a hose to the cylinder. They switched to a custom cylinder with a rigid fluid line and a port that provides easy access to the cylinder. This saved them installation time and eliminated the need for additional hose.
Early onset failure is common with standard cylinders. One company realized this when trying to use catalog rollers as supports for a self-propelled sprayer. The real problem seemed to be the seals. To keep his hydraulics running, the customer opted for a custom option that included a new seal package specifically designed for high speeds and severe pressure increases.