RU2560650C1 - Pneumohydraulic unit - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: pneumohydraulic unit consists of the cylinder 1 with the gas cavity 2 and the trunk piston 3 driven by the cranked shaft 4 through the rod 5. The cylinder 1 is connected to the crankcase 6 with formation of the subpiston cavity 7 the part 8 of which is filled with gas, and the part 9 - with liquid. The cavity 2 contains the suction 10 and the injection 11 valves, and the cranked shaft 4 - counterbalances 12 and 13. The counterbalance 12 functions as a device which alternately connects the cavity 9 with the source of liquid through the suction line 14 and with the consumer of liquid through the injection line 15 and the cooling jacket 16. The unit design provides also control of opening and closing of windows 17 and 18 by means of the slide valve operated by the cam installed on the crankshaft 4.

EFFECT: forced control of liquid flows passing through the unit housing allows to increase the frequency of back and forth motion of the piston and to improve mass-dimensional parameters of the unit.

4 cl, 11 dwg

Description

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

Known pneumohydraulic unit containing a cylinder with a piston and gas distribution bodies and a crankcase having a suction and discharge bodies connected respectively to a source and a consumer of liquid (see, for example, the USSR AS No. 1078126 of 03/07/84, MKI F04B 39/06, RF patent No. 118371 dated July 20, 2012, MKI F04B 19/06).

Also known is a pneumohydraulic unit containing a cylinder with a tron piston driven by a crankshaft, and gas distribution bodies and a crankcase directly connected to the cylinder and having suction and discharge bodies connected respectively to a source and a consumer of liquid (see, for example, RF patent No. 125635 dated 03/10/2013).

A disadvantage of the known designs is the inability to operate at sufficiently high frequencies (up to 50 Hz), characteristic of the economical operation of reciprocating compressors due to the fact that the distribution of the liquid is done by self-acting valves having a high inertia and hydraulic resistance due to the high viscosity of the liquid, due to which the real frequency of operation of such machines is a maximum of 8-12 Hz, and therefore they have poor overall dimensions.

The objective of the invention is to increase the overall dimensions of the pneumohydraulic unit by increasing the frequency of the reciprocating motion of the piston.

This problem is solved by the fact that in the known pneumohydraulic unit, the hydrodistributing bodies are made in the form of windows (through holes) in the crankcase wall, and the crankshaft is equipped with a device providing alternating connection of the crankcase with the source and consumer of the fluid. This device can be made in the form of a counterweight mounted on the crankshaft or made with it in one, and the counterweight is located with the possibility of overlapping the said windows in the crankcase. Also, a device that provides alternating connection of the crankcase with a source and a consumer of liquid can be made in the form of a profiled cam mounted on the crankshaft, interacting with the movable spool rod, and this cam can be made in the form of a counterweight.

The invention is illustrated by drawings.

In FIG. 1 shows a cross section of a pneumatic hydraulic unit along the axis of the cylinder perpendicular to the plane in which the connecting rod moves.

In FIG. 2-5 show the sequential position of the piston with the movement mechanism and a counterweight in a plane parallel to the plane of movement of the connecting rod.

In FIG. 6 shows a sectional view of a fluid flow control unit using a spool controlled by a cam mounted on a crankshaft; FIG. 7-10 show a side view of a cam with a side valve in sequential positions, and in FIG. 11 is a section of the unit with a counterweight that simultaneously performs the function of a cam.

Pneumohydraulic unit (Fig. 1-5) consists of a cylinder 1 with a gas cavity 2 and a thron piston 3 placed therein, driven by a crankshaft 4 through a connecting rod 5, and the cylinder 1 is directly connected to the crankcase 6 with the formation of a piston cavity 7, part 8 of which is filled with gas, and part 9 is filled with liquid. The gas cavity 2 contains a suction 10 and 11 injection valves, and counterweights 12 and 13 are installed on the crankshaft 4, and the counterweight 12 acts as a device that alternately connects the cavity 9 with a fluid source through the suction line 14 and with the fluid consumer through the discharge line 15 and the jacket cooling 16. This connection occurs with open windows (through holes) 17 (discharge window) and 18 (suction window), which are located (Fig. 2) directly in the wall of the crankcase 6 and overlap with the counterweight plane - e end face when passing the counterweight 12 opposite the windows 17 and 18.

When used as a device that alternately connects the crankcase with the source and the consumer of the liquid, mounted on the crankshaft 4 or made with one profiled cam 19 (Figs. 6 and 7), the latter interacts with the movable spring-loaded stem 20 of the spool 21 having a recess 22, alternately connecting the suction line 14 with the suction window 18 and further with the cavity 9, and the discharge line 15 with the window 17 and further with the cavity 9.

Pneumohydraulic unit operates as follows (Fig. 1).

When the crankshaft 4 is rotated, the piston 3 makes a reciprocating motion, as a result of which the volumes of the gas cavity 2 and the piston cavity 7 change. When the volume of the cavity 2 increases, a vacuum appears in it, as a result of which the suction valve 10 opens, the pressure valve 11 closes, and there is a process of absorption from the gas source. After passing the bottom dead center (BDC), the piston 3 moves up, the volume of the cavity 2 decreases, the pressure in it rises above the pressure of the gas source, valve 2 closes. With the further movement of the piston 2 upward, the gas pressure becomes higher than the discharge pressure of the gas consumer, the valve 11 opens, and gas from the cavity 2 is pumped to the consumer until the piston reaches the top dead center (TDC). Next, the process of the cavity 2 is repeated.

When the piston 2 moves from TDC downward, the pressure in the sub-piston cavity 7 and, accordingly, in its parts 8 (filled with gas) and 9 (filled with liquid) increases. This increase occurs as long as (see also Fig. 2), while the counterweight 12 closes the discharge window 17 with its end surface when the window 18 is closed. When the crankshaft 4 is rotated further and the piston 3 moves further down (Fig. 3), the discharge opens window 17 (with the window 18 closed), and the liquid from part 9 begins to move to the consumer through the liquid discharge line 15, passing through the jacket 16, cooling the cylinder 1, which is heated due to the heat of compression during operation of the cavity 2, thereby increasing the efficiency of work s of the cavity by cooling the gas and gas approximation to an isothermal compression process.

When the piston 2 approaches the BDC, the process of pumping liquid from part 9 ends (Fig. 4), and then the piston starts to move upward, while the window 17 is closed, but the window 18 is still closed, and the gas located in part 8 of the cavity 7 begins to expand , its pressure drops below the suction pressure of the liquid, after which the window 18 is opened by the end of the counterweight 12, and the process of suction of the liquid from the suction line 14 through the open window 18 with the window 17 closed begins. The suction process ends when the counterweight 12 closes the window 18. c cl repeated.

When used as a device periodically connecting part 9 of cavity 7 with suction and discharge lines 15, a spool 21, the rod 20 of which, together with the recess 22, is moved by a profiled cam 19 mounted on the crankshaft 4, the above-described operation cycle is carried out. In FIG. 6 and 7 show the moment corresponding to the moment shown in FIG. 2, when the piston 3 is in the TDC position and starts to move downward, the windows 18 and 17 are closed by the body of the rod 20. With a further piston stroke downward and a corresponding rotation of the cam 19 (see also Fig. 7), first in the cavity 7 (respectively, in the cavities 8 and 9) the pressure rises, then the injection window 17 (Fig. 8) opens, and liquid is injected. Further, the cam 19 together with the crankshaft 5 is rotated to the position shown in FIG. 9 (corresponds to the beginning of the upward stroke of the piston 3 — expansion of the cavity 7 and, accordingly, of the gas in the cavity 8), the windows 17 and 18 are closed by the rod body 20, after which, with a further upward movement of the piston 3, the suction line 14 is connected to the window 18 ( Fig. 10), and the process of absorption of the liquid begins. Subsequently, the cam 19 moves the rod 20 to its highest position (piston 3 is in the TDC position at the end of its upward stroke), and the cycle repeats again.

In the construction shown in FIG. 11, the cam 19 additionally performs the function of a counterweight, which makes it possible to minimize the volume of the cavity 8 and increase the degree of increase in pressure in it, and hence the degree of increase in the pressure of the liquid. In addition, the absence of counterweights in part 9 of the cavity 8 can significantly reduce the cost of work on mixing the fluid in the crankcase 6 during operation of the unit.

The proposed design of the pneumohydraulic unit allows you to organize the forced operation of the hydraulic distribution bodies (practically replace the self-acting liquid valves with a spool distribution), ensuring a reduction in the loss of work on the intake and injection of the liquid and the independence of the liquid distribution process from the rotational speed of the crankshaft, which allows to increase the frequency of the reciprocating motion of the piston to values characteristic of compressor machines, and thereby reduce weight and overall size s of the unit (to improve overall dimensions).

Claims (4)

1. Pneumohydraulic unit comprising a cylinder with a tron piston driven by a crankshaft and gas distribution bodies, a crankcase directly connected to the cylinder and having liquid hydrodistributing bodies connected to a source and consumer of liquid, characterized in that the hydrodistributing bodies are made in the form windows in the crankcase wall, and the crankshaft is equipped with a device that provides alternating connection of the crankcase with the source and consumer of the fluid. 2. Pneumohydraulic unit according to claim 1, characterized in that the device providing alternating connection of the crankcase with the source and consumer of fluid is made in the form of a counterweight mounted on the crankshaft or made with it in one, and the counterweight is located with the possibility of overlapping windows in the crankcase . 3. Pneumohydraulic unit according to claim 1, characterized in that the device providing alternating connection of the crankcase with the source and consumer of fluid is made in the form of a profiled cam mounted on the crankshaft, interacting with the movable spool rod. 4. Pneumohydraulic unit according to claim 3, characterized in that the shaped cam is made in the form of a counterweight.

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