Non-contact seals with fl at slott ed gaps of drives of electric power systems used in switchgears of hydraulic units, as well as in pumps and hydraulic motors have been investigated. Calculation of seals based on average clearance results in an underestimation or overestimation of the leakage rate compared to the operational values. The regularity of the distribution of pressure and fl ow rate in the gap of a fl at conical slot is determined, and formulas for the fl ow rate (leakage) and friction forces acting on the walls of the conical slot are found. To solve the problem, the approximate Navier-Stokes and fl ow continuity equations are used. Several special cases of the fl ow of the working fl uid in diff erent gaps are considered: a plane-parallel gap with an oscillating wall and at a constant pressure gradient and a conical gap at diff erent ratios of the pressure drop and the frictional action of the moving channel wall. When the wall oscillates in a conical gap and constant pressure, the presence of an extremum is characteristic. In this case, an excess pressure appeared in the slott ed gap, creating a supporting force, and the pressure value became high enough. When the lower wall of the conical slot moves in the direction of the increasing gap, the pressure inside the slott ed channel, under certain conditions, can reach a complete vacuum, the value of which is limited by the bulk strength of the liquid and the pressure of saturated vapor at a given temperature. When the pressure drop and oscillations of the wall of the conical gap are additive, then at a suffi ciently high velocity of the wall movement, the pressure inside the slot can even increase and exceed the value of the supplied pressure.

The influence of obliteration of slott ed gaps of plunger couples at the stage of design and calculation of drive systems for aggregates of electric power systems is considered. Obliteration is considered as a harmful phenomenon, on the basis of this, it is necessary to search for methods and means that contribute to the stabilization of flow. Such a problem arises whenever it is necessary to obtain small and stable over time fluid flow rates. Since obliteration is always accompanied by an increase in the forces required to move the mating parts relative to each other, for example, a plunger in a sleeve, ignoring this phenomenon can lead to underestimated costs of leakage of the working fluid. These efforts are all the more, the more active is the obliteration process. The analysis of experimental studies for various types of liquids with different gaps and pulsations of the pressure drop at the ends of the gap. The obliteration process, caused by the adsorption of liquid molecules, was approximated by an exponential function that allows you to determine the maximum possible thickness of the boundary layer of liquid formed on the channel wall.

The infl uence of the geometric dimensions and confi guration of slot contactless seals on the obliteration of the gaps of plunger pairs at the design and calculation stage of drive systems of electric power systems units is considered. The combined eff ect of working fl uid contamination and the adsorption eff ect on the overgrowth of the living section of the channel was revealed. The fl ow rate during sample shedding was reduced simultaneously as a result of the channel overgrowing with contamination particles and adsorption, i.e. the formation of boundary fi lms on the channel walls. Leaks through the gap at concentric and eccentric position of the plunger in the sleeve are determined. The minimum gap is found, at which the obliteration process is stabilized and loose mud formations are washed away by the fl ow of the working fl uid. The infl uence of the pressure drop at the ends of the slot gap on the channel obliteration process was revealed. With an increase in the pressure drop, the process of stratifi cation of adsorbed layers of polar molecules accelerates, resulting in an increase in the number of contamination particles trapped in the gap per unit of time. With an increase in the temperature of the working fl uid, the process of channel obliteration accelerates, which is confi rmed by experiments. With an oscillating plunger, the fl ow through the annular gap is less than with a stationary one. This is due to the fact that the oscillating plunger occupies a position in the sleeve close to the concentric one, at which leaks are minimal. A stable fl ow rate is obtained when the working fl uid fl ows through the gaps of the plunger pairs performing reciprocating oscillating movements.

The infl uence of the geometric dimensions and confi guration of slot contactless seals on the obliteration of the gaps of plunger pairs at the design and calculation stage of drive systems of electric power systems units is considered. The combined eff ect of working fl uid contamination and the adsorption eff ect on the overgrowth of the living section of the channel was revealed. The fl ow rate during sample shedding was reduced simultaneously as a result of the channel overgrowing with contamination particles and adsorption, i.e. the formation of boundary fi lms on the channel walls. Leaks through the gap at concentric and eccentric position of the plunger in the sleeve are determined. The minimum gap is found, at which the obliteration process is stabilized and loose mud formations are washed away by the fl ow of the working fl uid. The infl uence of the pressure drop at the ends of the slot gap on the channel obliteration process was revealed. With an increase in the pressure drop, the process of stratifi cation of adsorbed layers of polar molecules accelerates, resulting in an increase in the number of contamination particles trapped in the gap per unit of time. With an increase in the temperature of the working fl uid, the process of channel obliteration accelerates, which is confi rmed by experiments. With an oscillating plunger, the fl ow through the annular gap is less than with a stationary one. This is due to the fact that the oscillating plunger occupies a position in the sleeve close to the concentric one, at which leaks are minimal. A stable fl ow rate is obtained when the working fl uid fl ows through the gaps of the plunger pairs performing reciprocating oscillating movements.

The hydrodynamic parameters of the flow of a viscous working fluid in plane-parallel and conical gaps in drives of electric power systems are investigated. A general expression is found for determining the regularity of the change in the flow rate in the gaps of non-contact seals, and special cases are considered. In the case of frictional movement of one of the walls, the Couette flow is observed in the gap. When the pressure is applied to the liquid in the gap, a parabolic velocity distribution is observed with a maximum in the middle of the channel. Under the joint action of the frictional movement of the wall and the pressure flow in the channel, stratification of fluid movement in opposite directions is observed. Frictional flow in conical slots, when the fluid moves in only one direction, is possible at a taper value of -0,5...1,0. In all other cases, the flow in the slot will have two opposite flow directions. The presence of two opposite flows inside the slot can also be for the case when the direction of movement of the movable wall coincides with the direction of the pressure flow. This is caused by an increase in pressure within the gap. A general solution has been found for the pressure force in the gaps, which tends to push the walls apart, i.e. open the sealing surfaces. The analysis of the pressure force is carried out for various cases of the slotted gap and under various effects of the frictional flow and pressure head.