Application Of Hydraulic Components

Hydraulic components are widely used, many different expectations have been put forward. For example, they want to adapt to different working environments, such as severe cold and heat; Some of them should be corrosion-resistant, others should be explosion-proof. For mobile hydraulic, small volume and light weight are expected. For use in hospitals and offices, no leakage and low noise are required.

The following requirements are common.

(1) Excellent control and regulation characteristics

High stability and repeatability, fine adjustment, especially for valves.

(2) Withstand voltage performance

The working pressure of modern hydraulic technology is high, and there is often a very high pressure peak in an instant, which requires that the hydraulic components can withstand.

Because the pump is often the component with the highest working pressure and the longest working time in the whole system, the pressure resistance requirement of the pump is often the highest.

(3) Work persistence

For a hydraulic component, it is particularly valuable that it has good working durability (life) under high pressure and drastic pressure change.

There are many factors that affect the durability of the work, among which the most important factor is the lubrication condition and the material non-uniformity of the raw materials - impurities, gas content, etc.

The great progress of new materials and new technology is helpful to improve the working durability of hydraulic components.

(4) Stable manufacturing quality

That is, the consistency of manufacturing.

It is often measured by six sigma and ppm, that is, there are a million possible unqualified places in the seized finished products, and there are several unqualified places.

This is especially important for the main engine plants with mass production, such as automobiles, excavators, loaders, etc.

(5) Reliability

Reliability refers to the ability to complete specified functions under specified conditions and within specified time.

High reliability means that:

Be able to meet the requirements. Because the hydraulic components will be worn in the work, its performance can meet the requirements not only at the beginning of use, but also after long-term work.

Because there are always deviations in mechanical manufacturing, there are very few components that can not meet the requirements. For example, there are less than ten or even less than one in an average of one million.

Therefore, for hydraulic components, in fact, it is the comprehensive embodiment of excellent design performance and stable manufacturing quality. Any component in the hydraulic system will affect the normal operation of the whole system due to failure. The replacement of failed components not only means to pay for replacement parts and repair costs, but also means that the whole equipment must be suspended, which often exceeds the cost of replacement parts and repair. Therefore, in many cases, users prefer to pay a higher cost to buy components that are not likely to fail.

Nowadays, the reliability of hydraulic components has been measured by "mean time to failure (mttfd)". This is an index obtained from the durability test based on the sampling simulation of the actual working conditions. The probability of failure is less than 3.3%. It can be said that mttfd > 30 years; Only when the probability of dangerous failure is less than 0.6%, can we say that mttfd is more than 150 years, and most of the world's advanced hydraulic products have reached this level.

The above requirements for hydraulic components are the benchmark to measure the level of hydraulic components and divide the grades of hydraulic components.

(6) Market

The market of hydraulic components can be divided into pre market and post market, which have different demands.

Pre Market: provide components for main engine manufacturers, often called "OEM". Generally, the order quantity of each batch is large, but the requirements for performance consistency, service life (shelf life of at least one year) and payment terms are also relatively strong, especially for those first-class large factories.

Aftermarket: provide replacement parts. Although the requirements for performance consistency, service life (shelf life more than three months) are lower, the requirements for small batch and low price are often stronger.

Of course, customers' affordability to price is also different. Cost performance is a very sensitive indicator, which also plays a very important role in the development of technology.