Electric Roller Shutter Doors for Hydraulic Freight Lifts: Flexible Landing Door Control

Electric roller shutter doors are a practical landing-door solution for hydraulic freight lifts.

When the lift arrives at a floor, the roller shutter door automatically opens. Before the platform leaves, the door closes first and then the lift begins to move.

One customer wanted the door to remain closed while the lift was parked.

Rather than simply accepting the standard operation, this smart customer modified the control program himself.

He changed the current-floor button logic:

Press once → Door closes.

Press again → Door opens.

The lift platform remains stationary during this operation.

The roller shutter door operates at approximately 0.2 m/s, allowing a door slightly over 2 meters high to open in around 10 seconds.

This project demonstrates how customer experience and customized PLC programming can make hydraulic freight lifts more flexible and practical for real-world applications.

Full article:

https://beaconindustriesltd.com/blogs/knowledge/electric-roller-shutter-doors-for-hydraulic-freight-lifts-automatic-floor-access-and-flexible-control

Hydraulic Lift Solenoid Valve: Working Principle, Wiring and Troubleshooting

A solenoid valve is one of the key components used in many hydraulic lifting systems. It may look like a relatively small component, but it plays an important role in controlling hydraulic oil flow.

In our hydraulic lift systems, solenoid valves are commonly used to control the lowering function of the lift.

How Does a Hydraulic Solenoid Valve Work?

The working principle of a solenoid valve is relatively simple.

When electrical power is supplied to the solenoid coil, the coil generates a magnetic field. This magnetic force moves the internal valve spool and changes the hydraulic oil passage.

When the electrical power is removed, the solenoid is de-energized and the valve returns to its normal position.

A typical sequence is:

24V DC ON → Solenoid energized → Valve spool moves → Oil passage opens

The voltage does not have to be 24V in every application. Different solenoid valves can use different coil voltages, so the coil voltage must always match the electrical control system and the manufacturer's specifications.

How Does the Solenoid Valve Make a Hydraulic Lift Descend?

On many hydraulic lift power units, the solenoid valve controls the hydraulic oil return circuit.

When the lift is holding its position, the corresponding oil passage remains closed.

When the operator presses the DOWN button, the control box sends an electrical signal to the solenoid valve.

The sequence is:

DOWN signal → 24V DC output → Solenoid valve operates → Return passage opens → Hydraulic oil flows back to the tank → Lift descends

Once the hydraulic oil can return to the tank, the platform can descend under the effect of gravity and the load acting on the lifting system.

When the DOWN signal is removed, the solenoid is de-energized and the valve returns to its normal position.

How Is a 24V Solenoid Valve Wired?

A commonly used 24V DC solenoid valve is relatively simple to connect.

The two coil terminals are connected to the corresponding control wires from the electrical control box.

For a solenoid connector with an indicator light, the light provides a useful visual indication of whether the coil is receiving electrical power.

When the DOWN command is activated:

24V ON → Indicator light ON → Solenoid energized

When the DOWN command stops:

24V OFF → Indicator light OFF → Solenoid de-energized

This simple indicator can be very useful during installation and troubleshooting.

What Is the Ground/Earth Terminal?

Some solenoid valve connectors also include a protective earth/ground terminal.

This terminal is different from the two coil terminals. The coil terminals supply power to operate the solenoid, while the protective earth connection is intended for electrical safety.

Whether the protective earth terminal should be connected depends on the specific valve, connector, electrical system, manufacturer instructions, and applicable electrical standards.

Therefore, the manufacturer's wiring diagram and applicable electrical regulations should always be followed.

How to Troubleshoot a Hydraulic Lift That Will Not Descend

If a hydraulic lift does not descend, the solenoid valve is one of the components worth checking.

First, check whether the DOWN command is being received by the control system.

Next, use a multimeter to check whether the expected voltage is being supplied to the solenoid coil when the DOWN command is active.

If the solenoid connector has an indicator light, check whether it turns on.

If there is no indicator light and no voltage, the problem may be related to the control signal, PLC output, relay, wiring, fuse, or power supply.

If the correct voltage is present but the solenoid does not operate, the solenoid coil or valve itself may need to be inspected.

If the solenoid operates normally but the lift still does not descend, the problem may be somewhere else in the hydraulic circuit, such as the valve spool, return passage, hydraulic pressure, or another hydraulic component.

Final Thoughts

A hydraulic solenoid valve is a small component with an important job.

By converting an electrical control signal into mechanical valve movement, it allows the electrical control system to control hydraulic oil flow.

For a typical hydraulic lift:

Electrical signal → Solenoid valve → Hydraulic oil passage → Oil returns to tank → Lift descends

Understanding this basic process makes installation, commissioning, and troubleshooting of hydraulic lifting equipment much easier.

For hydraulic lift manufacturers and users, knowing how to check the solenoid valve, its electrical signal, and the hydraulic circuit can significantly reduce troubleshooting time.

Every Roller Has a Record: How We Prepare for Future Maintenance

A lifting machine can contain hundreds of components.

Some are large and easy to notice, such as hydraulic cylinders and structural frames. Others are much smaller, but they are still critical to the movement of the machine.

Rollers are one of these components.

At Beacon Industries, we create 3D drawings and technical records for the rollers used in our lifting equipment projects.

Why Record Such a Small Component?

Because a roller is not just a simple wheel.

In many lifting mechanisms, rollers guide moving parts and help maintain smooth movement. We often think of them as the joints of the machine.

The roller needs to match the machine precisely.

Its diameter, width, shaft dimensions, bearing, and installation position all need to work together.

Even a small dimensional difference can affect the way a moving structure operates.

That is why we don't want to rely on memory when it comes to these parts.

We Create a 3D Model for Each Project

During the manufacturing process, the rollers and machined parts are documented with 3D drawings.

The project record can include:

• Roller dimensions

• Bearing model

• Shaft dimensions

• Matching parts

• Special project requirements

This creates a digital reference for the components actually used in the machine.

It is particularly useful because different customers and different machines may require different roller sizes.

What Happens If a Roller Needs to Be Replaced?

This is where the records become especially valuable.

Suppose a lifting machine has been working for several years and one of its rollers eventually needs to be replaced.

Without the original technical information, the replacement process may require measuring the old part and identifying the bearing again.

With our project records, we can retrieve the original data.

The roller dimensions and bearing model are already documented.

This allows us to quickly determine what was originally used and prepare the correct replacement.

Small Details Can Make a Big Difference

When people look at a lifting machine, they usually focus on the overall structure.

But reliable operation is often the result of many small details working together.

A correctly sized roller.

A properly selected bearing.

The correct shaft dimensions.

The right fit between components.

All of these details contribute to smooth operation.

This is why we believe that engineering records are just as important as the manufacturing process itself.

Manufacturing Today, Maintenance Tomorrow

A machine may leave our factory today, but it can continue working for many years.

We therefore try to preserve important engineering information for the future.

The purpose of keeping 3D roller drawings is simple:

If a component needs to be replaced in the future, we want to have the correct information ready.

No guessing.

No unnecessary redesign.

No searching for old dimensions.

Just retrieve the project record and identify the original specification.

That is one of the small ways we try to make our lifting equipment easier to maintain over the long term.

Good manufacturing builds the machine. Good documentation helps keep it running.

Why Hydraulic Cylinder Pin Retaining Nuts Are Better Than Cotter Pins for Lifting Equipment

 When designing hydraulic lifting equipment, every connection point must be reliable. The hydraulic cylinder pin is a key component that connects the hydraulic cylinder with the lifting structure and carries important mechanical forces.

To prevent the cylinder pin from moving out during operation, many traditional machines use cotter pins. However, for equipment that works under heavy loads and continuous vibration, a stronger locking method can provide better protection.

A hydraulic cylinder pin retaining nut system is designed to improve safety and durability.

The system consists of:

• Hydraulic cylinder pin

• Two locking nuts

• Retaining washer

After installation, the two nuts and retaining washer create a secure anti-loosening structure. The washer locks the nut position mechanically, reducing the possibility of loosening during long-term operation.

Compared with cotter pins, retaining nuts offer:

✔ Stronger fixing performance
✔ Better vibration resistance
✔ Longer working life
✔ Higher reliability for industrial applications

If a hydraulic cylinder pin moves out of position, the hydraulic cylinder may become unstable and affect the safe operation of the lifting equipment. Therefore, choosing a reliable locking method is an important part of equipment design.

This solution is suitable for many hydraulic lifting products, including scissor lifts, home lifts, cargo lifts, and guide rail lifting platforms.

Learn more:
https://beaconindustriesltd.com/blogs/knowledge/why-hydraulic-cylinder-pin-retaining-nuts-are-safer-than-cotter-pins-in-lifting-equipment

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