Development of hydraulic pump and motor
Development of hydraulic pump and motor
In 220 BC, Archimedes, the Greek, proposed the principle of object buoyancy, invented the screw pump and water lifting tool (Fig. d), the Egyptians used hot air and water to drive the temple gate and the water wheel in China, which can be said to be the oldest application of hydraulic technology.
In 1648, B. Pascal of France put forward the basic law of pressure transmission in liquid, which laid the foundation of hydraulic technology.
In 1795, Joseph bramah, an Englishman, used water as working medium for the first time in London, applied hydraulic technology to industry in the form of hydraulic press, and registered the British patent of the first hydraulic press; two years later, he made hydraulic press with manual pump for liquid supply. During the British Industrial Revolution in the 1850s, William George Armstrong used the steam engine to drive the hydraulic source of the water pump, which made the hydraulic press practical and invented and applied the hydraulic accumulator.
In the 19th century, water was used as the working medium of hydraulic transmission device in industry. The sealing problem of hydraulic transmission device was not solved well, and the emergence and competition of electric transmission technology once led to the stagnation of hydraulic technology. It was not until the beginning of the 19th century that the Americans first introduced mineral oil into the hydraulic transmission medium of liquid transmission and applied it to engineering practice In 1905, Janney first introduced mineral oil into the liquid drive, and designed and developed an axial piston pump and its hydraulic device (E); in 1906, the US warship Virginia used hydraulic drive instead of electric drive for gun lifting and longitudinal operation, and mineral oil instead of water as the hydraulic medium. The introduction of mineral oil improves the lubrication and sealing of friction pairs of hydraulic components. The introduction of materials and surface treatment technology, and the development of design theory and method of dynamic and static pressure bearing provide favorable conditions for the high pressure of hydraulic components, making the contemporary hydraulic pump and motor reach the rated pressure of 40MPa or even higher.
As an important hydraulic component, the piston pump in the hydraulic pump was first used. Gear pump is also an earlier hydraulic pump. Serviere pump, which is similar to the external gear pump, appeared as early as 1593. The rudiment of vane pump came into being at the end of the 16th century, but it was not until the invention of double acting vane pump by American Vickers in 1925 that it became a perfect form. The basic structure of this kind of pump is still adopted all over the world. The radial piston pump invented by hele Shaw in 1910 provides a kind of hydraulic energy element with compact structure and high pressure for hydraulic technology. This kind of pump is still used until 1960s. In 1922, Swiss Hans Thoma invented Thoma type axial piston pump. At first, flat valve plate was used and driven by universal hinge. Later, spherical valve plate was used. This kind of pump led to the development of a series of axial piston pumps with the most widely used high pressure system, such as the original single hinge pump, double hinge pump, and later hingeless pump and slipper pump. In 1940s, Sweden and the former Soviet Union developed and established the structure and design theory of screw pump with stable flow and low noise.
With the development of modern industrial technology and microelectronic technology, in recent years, there are many new products and structures, such as compound hydraulic pump, ultra-high pressure hydraulic pump, electro-hydraulic proportional servo control hydraulic pump, electro-hydraulic digital pump and water hydraulic pump, which are widely used in industry, agriculture, national defense and other fields.
The radial crank connecting rod motor produced by Chamberlain hydraulic components company is one of the earliest low-speed and high torque hydraulic motors. After 1950s, many countries developed a variety of radial piston low-speed hydraulic motors, which created favorable conditions for direct hydraulic drive without deceleration device. For example, in 1970, the appearance of the low-speed high torque inner curve hydraulic wheel motor in hergrond, Sweden, can be directly installed into the wheel shell of the wheel due to its small size and light weight, which brings a revolution to the hydraulic transmission system and creates a new situation for the application of hydraulic transmission in vehicles and lifting and transportation machinery. In recent years, many new structures have been developed and developed, the number of which is increasing year by year and widely used in various industrial sectors.
China's hydraulic technology has developed with the establishment and development of new China. Since 1952, the first hydraulic component gear pump in China was trial produced, after more than 60 years of efforts, great progress has been made in self-development, technology introduction and implementation of international standards, and China's hydraulic industry has formed a relatively complete category with certain production capacity and technical support Flat industrial system. In recent years, a number of new technologies and products with independent intellectual property rights have been developed. As far as hydraulic pumps and motors are concerned, new products such as composite structure hydraulic pumps, ultra-high pressure hydraulic pumps and electro-hydraulic proportional, servo, digital pumps and special hydraulic motors for vehicles and construction machinery, together with traditional pump / motor products, basically meet the requirements of various main equipment used in industry, agriculture, National defense, science and technology and even people's material and cultural life facilities as well as rescue and disaster relief Demand for pumps and hydraulic motors.
At present and in the future, the technical development trend of hydraulic pump and hydraulic motor is to improve reliability and efficiency, reduce vibration and noise, improve the level of electro-hydraulic integrated control, improve the pressure and speed of hydraulic pump, improve the low-speed stability and speed range of hydraulic motor, and develop energy-saving and environment-friendly pure water hydraulic pump and hydraulic motor products.