The power performance of construction machinery is one of the most important indicators for measuring product technology level. It includes two parts: the power performance of the diesel engine itself and the comprehensive system performance of the machine's power transmission. In addition to continuously improving fuel injection systems and reducing fuel consumption and low-carbon emissions, construction machinery engines also have specific requirements for torque reserve and power output modes at low speeds, performance matching, and vibration and noise. At present, engines matched to China's construction machinery products include Weichai, Shangchai, Cummins, Deutz, Perkins, Isuzu, Yanmar, and others. High-end products, export equipment, large-tonnage equipment, and excavators almost entirely rely on foreign brands.

　　Transmission components specially used in construction machinery include the "dual-transmission system," planetary slewing reducers, drive axles and suspension systems, slewing bearings, "four wheels and one track," and others. At present, China's R&D level and R&D methods for construction machinery transmission components lag behind advanced international levels by about 30 years. Few domestic enterprises can undertake enclosed test methods for loading working-condition load spectra, and the precision and performance of transmission gears also lag far behind advanced international levels.

　　Hydraulic components are one of the key components of construction machinery products. They not only reflect the overall operating efficiency, simplicity, and comfort of construction machinery products, but are also a major source of faults in machine operation. In line with the theme of the conference, I will mainly introduce the development status of the hydraulic components industry supporting excavators.

　　For a long time, in high-pressure and large-flow hydraulic devices, the products of domestic component enterprises have found it difficult to meet the matching requirements of host machine enterprises, making imports the only choice, especially in excavator products. However, the high prices have led to the reality that they "consume 70% of the profits of the construction machinery industry" and to a long-term passive situation of being controlled by others.

　　China has now become the most important production and sales market for excavators, yet their core technologies and key components have always been an unspeakable pain in the development of domestic enterprises. Hydraulic pumps, hydraulic valves, hydraulic motors, and hydraulic cylinders are controlled by a few enterprises. At present, excavator hydraulic systems in China mainly use Japanese and Korean products. But what makes us proud is that Jiangsu Hengli High-pressure Cylinder Co., Ltd. has taken the lead in breaking through the bottleneck of localization. Its high-pressure cylinders have fully achieved matching with branded host machines and are being supplied globally. On 400 mu of newly acquired land in Wujin Development Zone, Jiangsu, it will bring 200,000 high-pressure cylinders to the industry each year. Its target market is already global, and it participates in the world's highest-level market competition.

　　Hydraulic pumps and hydraulic valves have higher technical content than hydraulic cylinders. Although no domestic enterprise has yet truly achieved large-scale matching, during the "Eleventh Five-Year Plan" period, under the attention of the state and industry associations and amid huge market demand, a large number of outstanding enterprises emerged in China. Taking revitalizing the national industry as their mission, they are determined to equip China's mobile machinery with a "Chinese core." Below, taking Longyuan Hydraulics, Zhongchuan Hydraulics, Boyi Hydraulics, Suqiangge Hydraulics, and Saikesi Hydraulics as examples, I will introduce the current development level of China's construction machinery hydraulic components industry in hydraulic pumps and hydraulic valves.

　　Longyuan Hydraulics, founded in 1998, has grown from a single agricultural machinery parts enterprise into a modern enterprise integrating R&D, production, and service of various hydraulic component systems. Its most competitive product at present is high-pressure cylinders for excavators, which have achieved matching with more than 30 domestic brand host machines. It is another leader in the excavator high-pressure cylinder industry. In 2010, in order to further meet market demand, it invested 500 million yuan and acquired 200 mu of land, with plans to introduce 8 high-pressure cylinder production lines, 1 high-pressure oil pipe production line, and 2 construction machinery fuel tank production lines.

　　Zhongchuan Hydraulics is by far the largest hydraulic project in China in terms of investment scale, with a total investment of 2.6 billion yuan. After reaching full production, it can produce 600,000 sets of high-end hydraulic components annually, achieving sales revenue of 6 billion yuan and profits and taxes of 1.31 billion yuan. Total investment is 520 million yuan, including 460 million yuan in equipment investment. All 148 pieces of equipment in the first phase have been commissioned, with a designed production capacity of 100,000 sets of hydraulic components. Small-batch trial production is now underway. Pumps, valves, and motors have been successfully trial-produced and have passed 200-hour bench tests.

　　Anhui Boyi began R&D on products such as hydraulic pumps, multi-way valves, and hydraulic motors in 2008. It has now successfully developed high-pressure swashplate axial piston pumps for 13t to 30t excavators, two types of 8-section multi-way valves with a diameter of ￠22, and one type of 8-section multi-way valve with a diameter of ￠19. It has overcome difficulties in melting and casting complex brass alloys and ductile iron, and solved technical difficulties in the bimetal casting process of complex brass alloys with carbon steel and alloy steel, including low bonding strength, low qualification rate, porosity, and blowholes.

　　Changyuan, a manufacturer of medium- and high-pressure gear pumps and hydraulic systems for industrial vehicles, began building an excavator cylinder production line in 2009 and started R&D and production of excavator multi-way valves. At present, cylinders for excavators below 13t have been matched in small batches on host machines, and cylinders for 22t excavators have been used on host machines for more than 1,000 hours; multi-way valves for 6t excavators have been trial-used on host machines for more than 500 hours, and multi-way valves for 8t and 23t excavators have also entered the sample trial-production stage.

　　Saikesi has focused on developing hydraulic components for small excavators since 2006. It has now developed OEM-series main hydraulic pumps and slewing/traveling motors for 4t, 6t, and 8t small excavators and has achieved batch matching with excavators in the Shandong area. It is currently developing hydraulic components for 10t and 12t machines. To solve host machine matching and achieve large-scale production of OEM hydraulic components, it will soon acquire 200 mu of land and invest 500 million yuan to vigorously expand component production lines, ensuring both parts and components are covered. At the same time, the company is about to introduce a team of senior Japanese experts in manufacturing to carry out on-site improvements.

　　In addition to the above enterprises, there are also a large number of national enterprises working quietly, such as AVIC Liyuan, AVIC Fengyang, Suqiangge Hydraulics, Lilong Hydraulics, Beijing Huade, Dagang Yining, and Jiangsu Ruilong. Their developed products are also being matched to host machines in small batches. To address the backward status of components, leading domestic construction machinery enterprises such as XCMG, LiuGong, and Zoomlion have begun to increase R&D efforts in components. XCMG Group is currently acquiring two component manufacturers in Europe through its listed company XCMG Machinery, one in Germany and one in the Netherlands. At the same time, China's rapidly developing construction machinery industry has also attracted the attention of foreign hydraulic component enterprises. Recently, Nabtesco Corporation and Shanghai Electric Hydraulics & Pneumatics Co., Ltd. jointly decided to establish Jiangsu Nabtesco Hydraulic Co., Ltd., with the goal of building China's largest hydraulic motor production base. Caterpillar of the United States and Liyuan have also signed a cooperation agreement in Wuxi, mainly engaged in the production of hydraulic pumps and hydraulic motors for construction machinery. Doosan Mottrol, South Korea's largest hydraulic component manufacturer, after several years of analysis and investigation, has also recently settled in Jiangyin. Rexroth is also highly optimistic about China's unimaginable prospects for excavator development and has specially launched hydraulic control systems for the excavator field.