China OEM Reputable Hydraulic Cylinders From Manufacturers Reliable Support and 2 Years Warranty vacuum pump engine

Product Description

Knuckleboom loaders have become indispensable in the material handling industry, providing efficient and versatile solutions for various applications.

One of the key components that empower these machines is the hydraulic cylinder. With its robust design and exceptional power, the hydraulic cylinder plays a crucial role in enhancing the performance and functionality of knuckleboom loaders.

The integration of hydraulic cylinders in knuckleboom loaders has revolutionized the material handling industry.

Hydraulic cylinders are essential components in the operation of wheel skidders, which are widely used in forestry and construction industries. These powerful machines are designed to efficiently transport and load heavy logs and debris in rugged terrains.

The hydraulic cylinders in wheel skidders are responsible for providing the necessary force and control to perform various tasks, making them vital for the machine’s overall performance and productivity,enabling efficient and precise operation in forestry and construction industries.

Their ability to generate high forces, adjustability, and durability make them indispensable for lifting, carrying, and maneuvering heavy loads in challenging terrains.

Hydraulic cylinders are essential components in track feller bunchers, heavy-duty machines used in the forestry industry for tree harvesting and processing. These cylinders play a vital role in various functions of the machine, providing the necessary power and control for efficient operations.

Hydraulic cylinders are used for the stabilization and leveling of the track feller buncher. These cylinders help maintain the stability of the machine on uneven terrain, ensuring safe and secure operations. They allow the machine to adjust its position and balance to overcome obstacles and maintain stability during tree cutting and handling.

Hydraulic cylinders play a vital role in the operation of wheel feller bunchers, which are powerful machines used in the forestry industry for tree harvesting and processing.

These cylinders are essential for various functions, such as controlling the cutting head, the boom arm, and the grapple. By exerting hydraulic pressure, these cylinders provide the necessary force and precision to efficiently cut and process trees. 

About Us

Established in    1988   , HangZhou LD Machinery Co, LTD. (hereinafter referred to “LD”) is a leading manufacturer specializing in the design, research, development, manufacture and marketing in the hydraulic industry. Being one of major suppliers of customized components and cylinders for manufacturers spreaded all over the world, the company is committed to offer high quality products with competitive prices and excellent service worldwide.

Headquartered in HangZhou City, ZHangZhoug Province, the company wholly owns a subsidiary production factory named “HangZhou YUEWEI Hydraulic Technology Co., Ltd”, which covers an area of more than     380,000 square meters   , possesses abundant technical strength and sound production management system, superior machining production equipment, strict and effective quality control system, advanced and excellent inspection instruments.

More than     35    years experience in machining industry, with over     10    experienced technical engineers and     150    skilled workers, LD has a senior engineering technical team with special skills and rich experience in product design, casting, forging, and CNC machining, can handle special material, structure, defect and processing, meet the evolving needs, and provide optimal solution and real one-stop service to customers.

Hydraulic Cylinder Producing Process

Step1: Quality Control on Raw Material
We have our own lab in factory, inspect the raw material and do the test. For every batch of material we received, we will ask supplier provide their certificate, and then cut them to do the test again to see if the results match the certification. Also, every batch we received, we will cut them into pieces to check the air bubbles. Once they are all qualified, we will accept it, and all detail information will be recording in our ERP system. We will also pay lot of attention on the salt spray test for chrome rod. Every month, we will cut the material, put them into test machine to see if it reach the requirement. All the result will be recorded at our QC department. If customer need, we can provide it.

Step2: Quality Control on Machining

we start doing components machining from 1988 with 36 years experience now and insist doing 100% inspection. We spend lots of money, invest on auto robots and machines. Now half of the producing line is by robot so that we can ensure our quality be stable good. For every part of the cylinder, we do 3 times inspecting. Firstly, workers will do self inspection. Secondly, we have tour-hour inspection checking the products, 2 times in the morning and 2 times in the afternoon, make sure that every step is good. After the products are all completed, we will do 100% inspection. For thread, for the tolerance, everything, we need double check. Also, we have specific warehouse just for the measuring tools. Every inspector have their own measuring tool and we will check the measuring tools regularly to make sure they are all in good condition, so that the measuring results will be convincing.

Step3: Quality Control on Welding

We are qualified to AWS certification, which is very popular in North American market. First, for the visual test, we will make sure that every components are welded good, look beautiful. And the second, we need to check the penetration. We have more than 15 years experience, we do know what kind of designing angle can make the cylinder welding strong. Once we finish the first article, we will cut it and analyse the welding to see if it is fulfill the groove. And then do the radiographic testing to make sure there is no gap inside. What’s more, we will do the ultrasonic test to check the program for the robot. Now 80% of welding is doing by robot. Once the program confirmed, no 1 can change it unless the welding manager, and they only have 5% right.

Step4: Quality Control on Assembling
For assembling, we have some difference with others. The brand we uses for seals are all those famous brand like Aston, Parker, Hallite. The cylinder we give to our customer has 2 years warranty. For our company, we engrave our part number and manufacturing date for the quality warranty. So no matter for seals or any others, as long as they are parts of cylinder, if it is under 2 years, we will take responsibility for them. And we will do the test for every cylinder like for pressure after we finish assembling.

Step5: Quality Control on Painting
We have our half auto painting line. Right now, we can paint about 1500 cylinders per day, which is about 1 container. Before we do the painting, we will do the wash first and for every cylinder, we will test for hardness, thickness and adhesion to make sure the painting are all good, which will be recorded into OQC report, print out and stick on the box, ship to you with your products.

Step6: Hydraulic Cylinder Packing
For every cylinder, we have the stick to show the detail information like bore size, stroke and working pressure. And we will use individual plastic bag packing. If customer need, we can also use individual carton box packing. We will fasten 1 floor after 1 floor with plat, so customer can only cut what they need and other layer will still be fasten. Moreover, there will be plywood pallet or plywood box for customer choosing. We will also send the loading picture to customer after we ship them to make sure everything is well loaded in China.

Packing Reference

Order Process

Enterprise Features

Q1. What is LD product’s quality assurance?
100% inspection for each product before shipping with inspection rereport for tracking.

Q2: How long is the warranty on LD products?
The warranty is 2 years for general products since the date of shipment.

Q3: How LD deal with the quality problem during warranty period?
1. LD will take the corresponding cost caused by customer local reparing. 
2. LD will provide the product by free if the repair cost is higher than the product value, but the freight involved shall be borne by customer side.

Q4: How to ensure the order can be shipped on time?
LD will send the “production schedule” every week after receiving customers’ orders. If any delays, LD will inform customers 3 weeks in advance, so as to facilitate the customer to arrange the schedule.

Q5: Does LD offer delivery service?
Yes. LD has deep cooperation with logistics companies all over the world to provide customers with quick and convenient “Door-to-Door services”,including sea, air and express.

Q6: How LD control the product quality?
1. Raw materials: We will test the material of each batch of raw materials we receive, and the piston rod will be tested with salt spray. This is to ensure that the material of our products meets the requirements at the beginning.
2. Processing: We have the leading machining equipment, and obtained ISO9001 certification.
3. Welding: Our factory is equipped with welding robots, and has obtained the AWS certification.
4. Assembly pressure test: 100% testing with OQC report for cHangZhou. The seals we use are: Hallite, Aston and Gapi

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Certification: ISO9001
Pressure: Medium Pressure
Work Temperature: Normal Temperature
Acting Way: Double Acting
Working Method: Straight Trip
Adjusted Form: Regulated Type
US$ 300/Piece
1 Piece(Min.Order)




hydraulic cylinder

How do hydraulic cylinders handle the challenges of precise positioning and control?

Hydraulic cylinders are designed to handle the challenges of precise positioning and control with a combination of engineering principles and advanced control systems. These challenges often arise in applications where accurate and controlled movements are required, such as in industrial automation, construction, and material handling. Here’s a detailed explanation of how hydraulic cylinders overcome these challenges:

1. Fluid Power Control:

– Hydraulic cylinders utilize fluid power control to achieve precise positioning and control. The hydraulic system consists of a hydraulic pump, control valves, and hydraulic fluid. By regulating the flow of hydraulic fluid into and out of the cylinder, operators can control the speed, direction, and force exerted by the cylinder. The fluid power control allows for smooth and accurate movements, enabling precise positioning of the hydraulic cylinder and the attached load.

2. Control Valves:

– Control valves play a crucial role in handling the challenges of precise positioning and control. These valves are responsible for directing the flow of hydraulic fluid within the system. They can be manually operated or electronically controlled. Control valves allow operators to adjust the flow rate of the hydraulic fluid, controlling the speed of the cylinder’s movement. By modulating the flow, operators can achieve fine control over the positioning of the hydraulic cylinder, enabling precise and accurate movements.

3. Proportional Control:

– Hydraulic cylinders can be equipped with proportional control systems, which offer enhanced precision in positioning and control. Proportional control systems utilize electronic feedback and control algorithms to precisely regulate the flow and pressure of the hydraulic fluid. These systems provide accurate and proportional control over the movement of the hydraulic cylinder, allowing for precise positioning at various points along its stroke length. Proportional control enhances the cylinder’s ability to handle complex tasks that require precise movements and control.

4. Position Feedback Sensors:

– To achieve precise positioning, hydraulic cylinders often incorporate position feedback sensors. These sensors provide real-time information about the position of the cylinder’s piston rod. Common types of position feedback sensors include potentiometers, linear variable differential transformers (LVDTs), and magnetostrictive sensors. By continuously monitoring the position, the feedback sensors enable closed-loop control, allowing for accurate positioning and control of the hydraulic cylinder. The feedback information is used to adjust the flow of hydraulic fluid to achieve the desired position accurately.

5. Servo Control Systems:

– Advanced hydraulic systems employ servo control systems to handle the challenges of precise positioning and control. Servo control systems combine electronic control, position feedback sensors, and proportional control valves to achieve high levels of accuracy and responsiveness. The servo control system continuously compares the desired position with the actual position of the hydraulic cylinder and adjusts the flow of hydraulic fluid to minimize any positional error. This closed-loop control mechanism enables the hydraulic cylinder to maintain precise positioning and control, even under varying loads or external disturbances.

6. Integrated Automation:

– Hydraulic cylinders can be integrated into automated systems to achieve precise positioning and control. In such setups, the hydraulic cylinders are controlled by programmable logic controllers (PLCs) or other automation controllers. These controllers receive input signals from various sensors and use pre-programmed logic to command the hydraulic cylinder’s movements. The integration of hydraulic cylinders into automated systems allows for precise and repeatable positioning and control, enabling complex sequences of movements to be executed with high accuracy.

7. Advanced Control Algorithms:

– Advancements in control algorithms have also contributed to the precise positioning and control of hydraulic cylinders. These algorithms, such as PID (Proportional-Integral-Derivative) control, adaptive control, and model-based control, enable sophisticated control strategies to be implemented. These algorithms consider factors such as load variations, system dynamics, and environmental conditions to optimize the control of hydraulic cylinders. By employing advanced control algorithms, hydraulic cylinders can compensate for disturbances and achieve precise positioning and control over a wide range of operating conditions.

In summary, hydraulic cylinders overcome the challenges of precise positioning and control through the use of fluid power control, control valves, proportional control, position feedback sensors, servo control systems, integrated automation, and advanced control algorithms. By combining these elements, hydraulic cylinders can achieve accurate and controlled movements, enabling precise positioning and control in various applications. These capabilities are essential for industries that require high precision and repeatability in their operations, such as industrial automation, robotics, and material handling.

hydraulic cylinder

Handling Challenges of Different Fluid Viscosities in Hydraulic Cylinders

Hydraulic cylinders are designed to handle the challenges associated with different fluid viscosities. The viscosity of hydraulic fluid can vary based on temperature, type of fluid used, and other factors. Hydraulic systems need to accommodate these variations to ensure optimal performance and efficiency. Let’s explore how hydraulic cylinders handle the challenges of different fluid viscosities:

  1. Fluid Selection: Hydraulic cylinders are designed to work with a range of hydraulic fluids, each with its specific viscosity characteristics. The selection of an appropriate fluid with the desired viscosity is crucial to ensure optimal performance. Manufacturers provide guidelines regarding the recommended viscosity range for specific hydraulic systems and cylinders. By choosing the right fluid, hydraulic cylinders can effectively handle the challenges posed by different fluid viscosities.
  2. Viscosity Compensation: Hydraulic systems often incorporate features to compensate for variations in fluid viscosity. For example, some hydraulic systems utilize pressure compensating valves that adjust the flow rate based on the viscosity of the fluid. This compensation ensures consistent performance across different operating conditions and fluid viscosities. Hydraulic cylinders work in conjunction with these compensation mechanisms to maintain precision and control, regardless of the fluid viscosity.
  3. Temperature Control: Fluid viscosity is highly dependent on temperature. Hydraulic cylinders employ various temperature control mechanisms to address the challenges posed by temperature-induced viscosity changes. Heat exchangers, coolers, and thermostatic valves are commonly used to regulate the temperature of the hydraulic fluid within the system. By controlling the fluid temperature, hydraulic cylinders can maintain the desired viscosity range, ensuring reliable and efficient operation.
  4. Efficient Filtration: Contaminants in hydraulic fluid can affect its viscosity and overall performance. Hydraulic systems incorporate efficient filtration systems to remove particles and impurities from the fluid. Clean fluid with the appropriate viscosity ensures optimal functioning of hydraulic cylinders. Regular maintenance and filter replacements are essential to uphold the desired fluid viscosity and prevent issues related to fluid contamination.
  5. Proper Lubrication: Different fluid viscosities can impact the lubrication properties within hydraulic cylinders. Lubrication is essential for minimizing friction and wear between moving parts. Hydraulic systems employ lubricants specifically formulated for the anticipated fluid viscosity range. Adequate lubrication ensures smooth operation and extends the lifespan of hydraulic cylinders, even in the presence of varying fluid viscosities.

In summary, hydraulic cylinders employ various strategies to handle the challenges associated with different fluid viscosities. By selecting appropriate fluids, incorporating viscosity compensation mechanisms, controlling temperature, implementing efficient filtration, and ensuring proper lubrication, hydraulic cylinders can accommodate variations in fluid viscosity. These measures enable hydraulic systems to deliver consistent performance, precise control, and efficient operation across different fluid viscosity ranges.

hydraulic cylinder

What is a hydraulic cylinder and how does it function in various applications?

A hydraulic cylinder is a mechanical actuator that converts hydraulic energy into linear force and motion. It plays a critical role in various applications where controlled and powerful linear motion is required. Hydraulic cylinders are commonly used in industries such as construction, manufacturing, agriculture, and transportation. Here’s a detailed explanation of what a hydraulic cylinder is and how it functions:

Definition and Components:

– A hydraulic cylinder consists of a cylindrical barrel, a piston, a piston rod, and various seals. The barrel is a hollow tube that houses the piston and allows for fluid flow. The piston divides the cylinder into two chambers: the rod side and the cap side. The piston rod extends from the piston and provides a connection point for external loads. Seals are used to prevent fluid leakage and maintain hydraulic pressure within the cylinder.


– The function of a hydraulic cylinder is to convert the pressure and flow of hydraulic fluid into linear force and motion. The hydraulic fluid, typically oil, is pressurized and directed into one of the chambers of the cylinder. As the fluid enters the chamber, it applies pressure on the piston, causing it to move in a linear direction. This linear motion of the piston is transferred to the piston rod, creating a pushing or pulling force.

Working Principle:

– The working principle of a hydraulic cylinder is based on Pascal’s law, which states that pressure exerted on a fluid in a confined space is transmitted equally in all directions. In a hydraulic cylinder, when hydraulic fluid is pumped into one side of the cylinder, it creates pressure on the piston. The pressure is transmitted through the fluid to the other side of the piston, resulting in a balanced force across the piston and piston rod. This force generates linear motion in the direction determined by the fluid input.


– Hydraulic cylinders find extensive use in a wide range of applications due to their ability to generate high forces and precise control of linear motion. Some common applications include:

1. Construction Equipment: Hydraulic cylinders are used in excavators, loaders, bulldozers, and cranes for lifting, pushing, and digging tasks.

2. Manufacturing Machinery: Hydraulic cylinders are employed in presses, machine tools, and material handling equipment for pressing, clamping, and lifting operations.

3. Agricultural Machinery: Hydraulic cylinders are used in tractors, harvesters, and irrigation systems for tasks like steering, lifting, and controlling attachments.

4. Transportation: Hydraulic cylinders are utilized in vehicles such as dump trucks, garbage trucks, and forklifts for tilting, lifting, and tipping operations.

5. Aerospace and Defense: Hydraulic cylinders are employed in aircraft landing gear, missile systems, and hydraulic actuators for control surfaces.

6. Marine and Offshore: Hydraulic cylinders are used in ship steering systems, cranes, and offshore drilling equipment for various lifting and positioning tasks.

In these applications, hydraulic cylinders offer advantages such as high force capability, precise control, compact size, and durability. They provide efficient and reliable linear motion, contributing to enhanced productivity and functionality in a wide range of industries.

Overall, hydraulic cylinders are integral components in various applications where controlled and powerful linear motion is required. Their ability to convert hydraulic energy into mechanical force makes them invaluable in numerous industries, enabling the operation of heavy machinery, precise positioning, and efficient load handling.

China OEM Reputable Hydraulic Cylinders From Manufacturers Reliable Support and 2 Years Warranty   vacuum pump engine	China OEM Reputable Hydraulic Cylinders From Manufacturers Reliable Support and 2 Years Warranty   vacuum pump engine
editor by CX 2024-01-23