(1) Product development, design and manufacturing barriers The manufacturing process of hydraulic products mainly includes product research and development, design, production and processing, debugging and testing, etc., involving the research and development of new materials, new processes and new structures, with long research and development cycles and complex production processes. Because different main engines and even different parts of the same main engine have different requirements for pressure, flow, and direction control, hydraulic component manufacturers often need to carry out high-matching personalized precision design and research and development according to specific customer needs, the scope of which covers materials. Research and development, integrated design, performance design, structural engineering design, appearance design and other parts are a multidisciplinary and complex technical operation that combines technical engineering and structural design. Enterprises entering the hydraulic components industry, especially the high-end hydraulic components industry, need to build a complete technology research and development platform and systematic and scientific product development process, and gradually accumulate and form relatively advanced hydraulic component product design, production and processing, debugging and testing and other research and development technical capabilities. To meet the increasingly personalized needs of customers in the constantly escalating and changing market environment. For new entrants, it is difficult to have the above-mentioned capabilities in a short period of time, so the level of research and development technology constitutes a barrier to the hydraulic components industry.

The upper slewing platform on the lower walking body of the hydraulic excavator is as important as the head and torso of the human body. Although its structure is difficult to see from the outside, if the engine and various hydraulic devices installed in it are faulty or overloaded, the overall state of the machine will be affected, performance will be degraded, and eventually machine failure will occur. Therefore, the daily maintenance and inspection of the upper slewing platform of the machine should be the first priority. In order to improve the working performance of the upper slewing platform and prevent unnecessary failure losses, what aspects should be paid attention to in the maintenance of the upper slewing platform?

Preparation before hydraulic pressure measurement (1) Hydraulic equipment 70kgf/cm2 (1000psi) 1 set of pressure gauge 400～500kgf/cm2 (5700～7100psi) 2 sets of pressure measuring equipment and 1 set of analytical instrument (2) Measurement of hydraulic oil cleanliness After air, open the cover and take out the sample oil from the tank, and then measure it with an analytical instrument. If the measured value is higher than the reference value, replace the return filter element or replace the hydraulic oil.

image.png 1. Before the excavator starts, check the environmental safety, clear obstacles on the road, and unrelated personnel leave the excavator and then lift the bucket. 2. After the preparation work, the driver should honk the horn first, and then operate the excavator to start. 3. Check the direction of the crawler frame before operating the walking lever, and try to make the excavator walk forward as much as possible. If the drive wheels are in front, the travel lever should operate backwards.

1. Unpacking: The oil cylinder is sealed with a vaporizable rust inhibitor, so the plug at the inlet must not be removed before assembly. If the plug is removed, it must be installed on the body immediately and the cylinder filled with oil 2. Anti-rust: After the oil cylinder is installed on the body, if the piston is placed in the extended state, grease must be applied to the exposed part of the piston rod.

A hydraulic motor is used to refer to an energy conversion device that outputs rotary motion and converts the hydraulic energy provided by the hydraulic pump into mechanical energy. ​From the point of view of energy conversion, the hydraulic pump and the hydraulic motor are reversible hydraulic components. Inputting working fluid to any hydraulic pump can make it work as a hydraulic motor; When the torque is driven to rotate, it can also become a hydraulic pump working condition. Because they have the same basic structural elements - a closed and cyclically variable volume and a corresponding oil distribution mechanism.