Eternal Hydraulic Cylinder is a professional hydraulic system solutions provider, belonging to the Eternal Group. Our products include hydraulic systems for dump trucks, truck cranes, dump truck cover plates, and garbage compression conveyors.
The company covers an area of 20,000 square meters and has an annual production capacity of 100,000 sets. We possess production lines for dump truck cylinders, special cylinders, heat treatment equipment, testing equipment, and over 500 CNC machining machines. The company currently has 30 sales personnel, 180 workers, and 40 R&D staff, 90% of whom hold a bachelor’s degree or higher, and 30% have overseas education backgrounds.
Eternal Hydraulic manufactures various types of hydraulic cylinders for different applications. Currently, it has the capacity to produce cylinders with diameters ranging from 32mm to 400mm and lengths up to 6000mm, with an annual production capacity of up to 300,000 units.
Testing Capabilities
We possess internationally advanced 2P-2F durability testing benches and reciprocating and buffer comprehensive performance testing benches. We conduct durability tests on hydraulic cylinders according to advanced international standards to ensure reliable cylinder performance. Our physicochemical and metallographic testing laboratories can accurately and reliably test the physical properties, chemical composition, and dimensional accuracy of materials.
R&D Tools
The R&D process utilizes a PLM management software platform (TeamCenter), combined with the SAP system and the YiPlatform system, to integrate and manage design, development, and production processes. This effectively controls every stage of product development from R&D to sales, providing effective technical support for Yinhua’s R&D management and development cycle.
Technical Highlights
* Key Force Theoretical Calculation, Analysis, and Verification of Hydraulic Cylinders
* Hydraulic Cylinder Buffer Technology
* Lightweight Hydraulic Cylinder Technology
* Large Circular Welding Technology
* Hydraulic Cylinder Corrosion Prevention Technology
* Slender Rod and Cylinder Machining Technology
* Intelligent Data Acquisition Technology for Hydraulic Cylinders
* Double-Acting Multi-Stage Cylinder Equal Thrust Technology
PDM Product Data Management Platform
* We have fully implemented PDM management, integrating with SAP systems, the YiPlatform collaborative office system, production visualization systems, and supplier procurement tracking systems to establish a parallel collaborative R&D environment across the enterprise.
Currently, the company comprises 22 manufacturing processes, possessing the capability to process 109 steps required for hydraulic cylinder production, with a 70% in-house parts manufacturing rate. To strictly control product quality stability, core processes (such as welding, heat treatment, electroplating, and spraying) and important parts are all produced internally, achieving advanced industry-leading technology.
1. Special Processes Process Control Capability
To ensure stable product quality, all key special processes are produced internally, with strict control over process parameters. The process follows four steps: process verification, process evaluation, production approval, and process monitoring, ensuring that process methods and parameters meet the requirements for part quality and product functionality.
● Process Validation: When new products are trial-produced or production conditions change, samples must be made according to product requirements and corresponding conditions. A Process Worksheet (PWPS) must be compiled for process validation to ensure that the process parameters meet quality requirements.
● Process Evaluation: Through various testing methods, the samples are evaluated to ensure that all performance characteristics meet relevant standard levels and product performance requirements, verifying the rationality of the PWPS.
● Production Approval: Based on the process evaluation results, the process parameters are solidified, and the PWPS is converted into a formal Production Worksheet (WPS). This signifies that the product is ready for small-batch production and can proceed with formal production according to the WPS.
● Process Monitoring: During the first few batches of production, the production process is monitored to ensure that personnel, machinery, materials, methods, and environment meet the process settings, and product quality remains stable.
2. Welding Technology
Welding technology is one of the core technologies in hydraulic cylinder production. The lifespan and performance of hydraulic cylinders are directly related to welding quality. Advanced welding technologies and processes are adopted to ensure the welding quality of the cylinders.
Gas welding technology
Friction welding technology
Welding quality control capability
Regarding welding process qualification, the company possesses various testing and experimental methods to fully verify welding reliability.
3. Electroplating technology
The chrome plating process utilizes the highly efficient HEEF-KR and CA-2000 hard chrome plating formulas, resulting in electroplated parts with a high number of microcracks, excellent corrosion resistance, and high hardness. General corrosion resistance reaches CASS level 9 for four cycles, with a hardness of HV900-1050. For special requirements, corrosion resistance can reach CASS level 9 or higher for ten cycles. To further enhance corrosion resistance, a multi-layer process of semi-bright nickel-bright nickel-hard chrome is also available.
The production line uses PLC full computer control, with nine pre-treatment and five post-treatment processes, ensuring stable plating quality. Fully automated control reduces labor intensity. High recovery rate of plating solution minimizes contaminants.
Process control is in place, with a comprehensive monitoring system and dedicated physicochemical analysts. Thickness and dimensional tests are performed on each piece on-site as required. Plating solution concentration is analyzed weekly, and chromium plating layer salt spray, adhesion, and hardness tests are conducted monthly.
Chromium plating of large workpieces is available, up to 6 meters in length and 400mm in diameter.
A stable and highly qualified chromium plating workforce is available. All workers undergo rigorous training, pass assessments, and obtain certification before being allowed to operate the equipment. Most employees have over 10 years of experience in chromium plating.
Coating Quality Control
● Hardness: Tested with a Vickers hardness tester, hardness HV800-1100 (GB/T9790)
● Chromium Plating Adhesion: Tested using the heating (rapid cooling) test method, the coating does not peel off (GB/T5270)
● Coating Salt Spray Test: Tested in a salt spray test chamber, CASS copper accelerated acetic acid test minimum 64h (GB/T10125)
● Porosity: Tested using the filter paper method, reaching grade 9 or above (GB/T17721)
4. Heat Treatment Technology
The heat treatment process is completed using an overall tempering equipment or a fully automatic surface induction heating equipment, and then subjected to hardness testing, tensile testing, and fully automatic metallographic analysis to ensure the heat treatment quality requirements are met. Process characteristics: Suspended heating, good uniformity, high temperature control accuracy, circulating and stirring quenching liquid, uniform cooling, controllable cooling rate, tempering metallographic structure rating ≤2, giving the parts good comprehensive mechanical properties and fully utilizing the material potential. Suitable for overall quenching and surface quenching of various shaft parts, with an annual processing capacity of 2200 tons of overall tempering and 6000㎡ of surface induction hardening for shaft parts.
5. Spraying Technology
Spraying is completed through a 315-meter fully automated electrostatic coating production line or a large-part manual coating production line. Coating quality is ensured through testing equipment for coating thickness, hardness, adhesion, and corrosion resistance. Waste gas generated during the coating process is treated by an integrated plasma photocatalytic VOCs treatment system, meeting emission standards. Our hydraulic cylinder coating uses electrostatic spraying, requiring 22 processes to form a film. Electrostatic spraying employs KEMLE air-mixing technology, combining the advantages of traditional air spraying and airless spraying. Automatic mixing of two-component paint and air achieves perfect control of the spraying interface, generating a very uniform coating film on the cylinder surface. Suitable for surface coating of various engineering machinery hydraulic cylinders. The largest hydraulic cylinder size for fully automated electrostatic coating is Φ350×2000, with an annual coating capacity of 160,000 cylinders.
The company possesses various types of testing and experimental equipment, with an original value exceeding ten million yuan. Its testing capabilities cover the entire production process of the company’s products. Currently, the company is able to conduct reliability and durability type testing, metrological verification and calibration, physicochemical analysis, and special characteristic testing.
Type testing utilizes imported testing equipment, capable of performing buffer tests, reciprocating durability tests, hydraulic lateral load reciprocating motion tests, 2P and 2F durability tests. The maximum test pressure reaches 75MPa, the maximum flow rate reaches 510L/min, and the total power of the testing machines reaches 500KW. With a wide testing range, it can provide reliability testing for hydraulic cylinders of various structures, providing essential means for comprehensive performance testing of the company’s products and further contributing to product development and improvement.
Metrological verification includes four grades of gauge blocks (length variation rate 0.0016~0.002‰), smooth ring gauges, and flat crystals, among other metrological standards. It also possesses precision testing instruments such as universal tool microscopes, force gauges, internal diameter gauge calibrators, and length measuring instruments. The metrology laboratory is responsible for the maintenance and management of over 2,000 length measuring instruments, portable testing equipment, and benchtop testing equipment. Its measurement traceability standards are reliable, providing a guarantee of measurement reliability for machining quality control.
The physicochemical laboratory possesses capabilities in mechanical property testing, metallographic analysis, various hardness tests, material composition analysis, and chemical analysis, meeting the company’s control needs for raw materials, special processing procedures, and environmental monitoring.
1. Deep Cultivation of Core Manufacturing Processes
As early as 2012, we launched a major expansion project for high-pressure hydraulic cylinders. This project involved a significant investment and featured a highly forward-thinking process approach:
* Cylinder Machining: Utilizing advanced scraping and burnishing processes, we ensured the smoothness, straightness, and dimensional accuracy of the inner bore, laying the foundation for stable cylinder operation and long service life.
* Surface Treatment: Piston rod electroplating employs a multi-layer nickel-hard chromium plating process, greatly enhancing wear resistance and corrosion resistance, enabling it to adapt to various harsh working conditions.
* Welding and Assembly: The introduction of welding robots and friction welding machines improved the consistency of welding quality for key structural components; the installation of assembly lines, automated painting lines, and computer-aided testing platforms modernized the manufacturing process.
2. Embracing Digital Transformation, Building a 5G Smart Factory
* Intelligent Production Management and Control: By deploying 5G+equipment data acquisition and 5G+MES (Manufacturing Execution System), the factory achieved real-time monitoring and optimized scheduling of production equipment, materials, and process parameters, making the entire production process transparent and manageable.
Intelligent R&D and Quality Prediction: The company’s technological innovation has penetrated deep into the field of artificial intelligence. We are developing a hydraulic component processing decision system, a parts processing quality prediction system, and a processing condition diagnosis system based on neural network models. These systems can predict processing results, optimize decisions, and diagnose equipment status through deep learning of massive amounts of process data, thereby proactively avoiding potential quality risks in the virtual world and shifting quality control from “post-inspection” to “pre-prediction.”
3. Continuous Structural Innovation and Integrated Design
In terms of specific product technologies, Eternal Cylinder focuses on solving practical application pain points. The company extends hydraulic technology to mechatronics integration, developing the Haitian injection molding machine integrated electro-hydraulic actuator, which highly integrates the motor, pump, valve, and cylinder, demonstrating its ability to evolve from a single component supplier to a system solution provider.