Lamellar hydraulic machine (slide, rotary hydraulic) - rotary volumetric hydraulic machine, in which two or more plates (sliders) are displacers. The term “plate-type hydraulic machines” should not be confused with the term “blade-type hydraulic machines”, because, according to the terminology currently adopted, the term “ blade-type hydraulic machines ” is assigned to hydrodynamic-type machines [1] .
Device and principle of operation
Lamellar hydraulic machines of single action and double action are made. Multiple action hydraulic machines are also known [2] . In single-acting machines for one revolution of the shaft of the hydraulic machine, the suction and discharge process is carried out once, in double-acting machines - twice.
Vane pumps can only be used in the hydraulic motor mode if there are springs in the space under the plates that press the plates against the stator housing. In the absence of such springs, the pump is not reversible.
The principle of operation of a single-acting pump is as follows. When the torque is communicated to the pump shaft, the rotor of the hydraulic machine rotates. Under the action of centrifugal force (or under the action of the elastic force of the springs located under the plates), the plates are pressed against the stator housing, as a result of which two cavities are formed, hermetically separated from each other. The volume of one of the cavities gradually increases (absorption occurs in this cavity), and at the same time, the volume of the other cavity gradually decreases (injection of the working fluid from this cavity).
Changing the working volume during operation is possible only in single-acting machines. However, in such hydraulic machines, a constant radial force acts on the rotor from the side of the high-pressure cavity, which leads to faster wear of the hydraulic machine parts. In double-acting machines of high-pressure cavities - two, and the radial forces are compensated by each other.
The change in the working volume (regulation of the hydraulic machine) is carried out by changing the eccentricity - the displacement of the rotor axis relative to the stator axis.
Lamellar hydraulic machines are able to operate at pressures up to 14 MPa [3] , the recommended rotation speeds usually lie in the range of 1000-1500 rpm [3] .
Compared to gears , plate hydraulic machines create a more uniform flow [4] , and compared to rotary piston and piston hydraulic machines they are cheaper, simpler in design and less demanding on filtering the working fluid.
Plate hydraulic machines are widely used in volumetric hydraulic drive systems (for example, in the drive of metal-cutting machines).
Advantages
- Relatively low ripple of supply (for pumps) and flow rate (for hydraulic motor);
- quite low noise level (in comparison, for example, with gear hydraulic machines );
- fundamental possibility to realize the adjustable volume;
Weaknesses
- design complexity and low maintainability;
- fairly low working pressures.
- sticking plates at low temperatures
See also
- Hydraulic machines
- Hydraulic drive
Notes
- ↑ Literature source 3
- ↑ Literature source 1, p. 4
- ↑ 1 2 Source of literature 2, p. 125
- ↑ Literature source 1, p. 3
Literature
- Vane pumps and hydraulic motors. Zaichenko I.Z. and Myshlevsky L.M. "Engineering", 1970. p. 229.
- Lepeshkin A.V., Mikhaylin A.A., Sheypak A.A. Hydraulics and hydropneumatic drive: Textbook, part 2. Hydraulic machines and hydropneumatic drive. / ed. A.A. Sheypak. - M .: MGIU, 2003 .-- 352 p.
- Vane pumps (centrifugal and axial). Terminology and letter designations. M., publishing house of the Academy of Sciences of the USSR, 1961.