RU2518796C1 - Machine of positive displacement action - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: machine consists of a cylinder 1 with a differential piston of U-shaped longitudinal section and two cavities: 3-pump one and 4 - compressor one. The inner part of the piston 2 is mating the outer surface of a crosshead lead-in segment 5 of U-shaped longitudinal section, the crosshead 6 is fitted by the inner lead-in segment along which the crosshead itself is sliding, the crosshead is hingedly coupled to a connecting rod 7 of a crank drive of the machine and coupled to the piston 2 via a rod 8. The piston 2 is fitted by a piston seal 9, and the crosshead lead-in 5 - by a seal 10. The inner cavity 12 of the piston 2 is connected with the suction line by a channel 11. Back pressure gas valves 13 and 14 are used to arrange the operation of the compressor cavity 4, fluid valves of the same type 15 and 16 - to arrange the operation of the pump cavity 3. U-shaped design of the piston and the crosshead lead-in provides for the creation of long seals at short length of the cylinder and piston group.

EFFECT: high leakproofness of operating cavities and reduced cross vibrations deteriorating the unit performance.

2 dwg

Description

The invention relates to the field of pump and compressor engineering and can be used to create volumetric reciprocating machines designed to compress and supply liquids and gases to a consumer simultaneously or alternately.

Known volumetric machine containing a cylinder and a differential piston with a rod, the lower part of the cylinder is filled with liquid and the upper with gas (see, for example, the USSR AS No. 1078126 according to the application 3513877 / 25-06, CL F04B 39/06, publ. 07.03.84, Bull. No. 9).

Also known is a volumetric machine comprising a crankcase, a cylinder with a differential piston disposed in it, connected to a crosshead having a guiding part, and dividing the cylinder into an upper compressor and lower pump cavity, which are connected to a source and consumer of gas and liquid, respectively, using self-acting reverse gas and liquid valves (see RF patent No. 118371, MKI F04B 19/06 dated July 20, 2012).

A disadvantage of the known structures is the large dimensions (extension) along the axis of the piston, which causes vibration of the piston group in the transverse direction relative to the axis of the piston, which contributes to increased wear and reduced operability of the structure, as well as difficulties with placing the machine in the compartments of mobile units, for example, in the engine compartment a car.

The objective of the invention is to increase the operability of the machine volumetric action and reduce its size.

This problem is solved by the fact that the longitudinal sections of the piston and the crosshead guide are made U-shaped with the formation of the inner and outer cylindrical surfaces, and the inner surface of the piston is made in the form of a counterpart of the outer guide surface of the crosshead.

The invention is illustrated by drawings.

Figure 1 shows a longitudinal section of a cylinder-piston group of the proposed device, and figure 2 is the same, but with an additional device for active cooling of the cylinder in order to increase the efficiency of the compressor cavity.

The volumetric action machine (Fig. 1) consists of a cylinder 1 with a differential U-shaped piston 2 in longitudinal section, which divides the cylinder 1 into two cavities - 3 (pumping) and 4 (compressor). The inner part of the piston 2 is associated with a minimum clearance with the outer surface of the U-shaped in the longitudinal section of the crosshead guide part 5, which has an inner guide part along which the crosshead 6 slides, pivotally connected to the connecting rod 7 of the crank drive of the machine, and connected to the piston 2 through the rod 8. The piston 2 has a piston seal 9 in the upper part, and the crosshead guide 5 has a seal 10, which prevents the working fluid from entering the pump cavity 3 into the crankcase of the crank drive (on figures not shown). Channel 11 connects the internal cavity 12 of the piston 2 to the suction line. Self-acting gas check valves 13 and 14 serve to organize the operation of the compressor cavity 4, and the same liquid valves 15 and 16 serve to organize the operation of the pump cavity 3. The annular liquid cavity 17 is connected to the pump cavity 3 and through the discharge liquid valve 15 to the fluid consumer .

The machine volumetric action works as follows (figure 1).

When reciprocating the crosshead 6 driven by the connecting rod 7 from the crank mechanism, the volumes of the compressor cavity 4 and the pump cavity 3 change, as a result of which the gas is sucked into the cavity 4, compressed there and pumped into the gas consumer, and the liquid is sucked into cavity 3, is compressed in it and supplied to the consumer fluid.

At the same time, there are practically no leaks of compressed gas in the machine, as even if it breaks through the O-ring 9, during the relatively short time of the compression and injection process it cannot manage to displace the liquid from the narrow extended gap between the outer surface of the piston 5 and the inner surface of the cylinder 1, and the liquid located in the extremely small and long gap between the inner surface of the piston 2 and the outer surface of the crosshead guide 5 6.

At the same time, a fluid having a dynamic viscosity an order of magnitude greater than gas cannot overcome the O-ring 9 during compression and injection, and minor leaks through a smooth narrow long gap between the outer surface of the crosshead guide 5 and the inner surface of the piston 2 are evacuated from the piston space through the channel 11 into the suction line, preventing the ingress of working fluid into the crankcase of the machine.

The design depicted in figure 2 works similarly to the above. The difference from the latter is that the working fluid having a low temperature is pumped to the consumer through the cavity 17 surrounding the cylinder 1, which leads to a decrease in the temperature of the latter, an increase in the amount of heat removed from the gas during compression, and thus, an increase in efficiency cars.

Thus, the proposed design of a volumetric machine with high tightness of the working cavities, provided, first of all, a large length of the sealing slots along the axis of the cylinder, has the dimensions of the piston group along the axis of the cylinder at least by the length of the piston less than that of the known design, which increases its stability , reduces the amplitude of the forced vibrations of the cylinder-piston group, which, in turn, increases the efficiency of the structure.

Claims (1)

A volumetric machine comprising a crankcase, a cylinder with a differential piston located in it, connected to a crosshead having a guide part, and dividing the cylinder into the upper compressor and lower pump cavities, which are connected to the gas and liquid source and consumer using self-acting gas and liquid valves, characterized in that the longitudinal sections of the piston and the crosshead guide are made U-shaped with the formation of inner and outer cylindrical surfaces, with than the inner surface of the piston is made in the form of a mate of the outer guide surface of the crosshead.

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