Comparison and selection of construction styles of four hydraulic pumps
The structural type hydraulic pump of the hydraulic pressure pump is a key component in the research and application of hydraulic transmission technology. Generally, hydraulic pumps are divided into four categories according to the structure: gear pump, vane pump, screw pump and plunger pump. However, the friction pair contact pressure of gear pump, vane pump and screw pump is relatively large. Concerned about surprises Label: distribution flow friction pair water pressure liquid control variable pump Previous: How to rust the rusty car surface? Next: Home daily hardware purchase skills
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The structural type hydraulic pump of the hydraulic pressure pump is a key component in the research and application of hydraulic transmission technology. Generally, hydraulic pumps are divided into four categories according to the structure: gear pump, vane pump, screw pump and plunger pump. However, the friction pair contact pressure of gear pump, vane pump and screw pump is relatively large. For example, during the rotation of the vane pump, the vane reciprocates linearly with respect to the rotor guide groove, and the lateral stress is maximized at the contact edge; in the high pressure region, the vane is subjected to centrifugal force and the bottom high pressure medium acts close to the inner surface of the stator. Because of the small contact area, the contact pressure is quite large.
According to the above analysis, it can be seen that the hydraulic pressure pump at home and abroad adopts the structural form of the plunger pump, one is the valve distribution type, including the valve distribution radial piston pump and the swash plate valve distribution axial piston pump; The type is a swash plate type distribution plate with an axial piston pump. The type of plunger pump can not only reduce the contact specific pressure of the friction pair, but also the main friction pair of the axial piston hydraulic motor (pump) is mostly designed by static pressure support method (and the gear pump or vane pump) There are high-line pairs of wire contacts, which greatly reduce the PV value of the friction pair, thereby reducing the power loss and wear of the friction pair, which is especially important for sea and freshwater hydraulic motors because the lubrication performance of the water medium is extremely poor. It is difficult to form an elastohydrodynamic lubrication effect between the friction pairs. Therefore, as the base pump portion of the variable pump, an axial piston type will also be employed.
The valve-fitted axial piston pump has a high resistance to contamination and, in certain applications, for example as a bilge-bottomed drain pump, has a long life and high reliability. Although the variable structure of the valve distribution pump is many, the structure is complicated and the scope of application is limited, which makes the manufacturing cost increase and the technical and economic indicators are unreasonable, and has not been widely used. There are many variable types of swashplate type distribution plate axial displacement piston pumps. According to the operation type, it can be divided into manual, motorized, electric, hydraulic control and electro-hydraulic proportional control. However, the basic principle is to change the inclination of the swash plate. Thereby changing the displacement of the pump to achieve the purpose of the variable. For the swash plate type distribution plate with axial piston pump, the structure has a swash plate rotating cylinder fixed and a swash plate fixed cylinder rotation. For the former type, to change the swashplate inclination to achieve the variable, the swash plate is required to both rotate and oscillate, and the variable piston needs to balance the axial thrust of all the plungers, so the structural design is difficult and the applicable surface is limited. For the latter version, since the swash plate is only swung, it is relatively easy to implement.