SU400737A1 - PISTON VACUUM PUMP - Google Patents

Description

The invention relates to the field of vacuum pump construction. Piston-type double-acting vacuum pumps with spool gas distribution along the main engine are known. St. N ° 159925. However, the well-known piston vacuum pumps have not sufficiently high performance in a single-stage pumping mode. For the sake of exhaust cavities of the spool cylinder in a single-stage pumping mode in the proposed pump, these cavities are connected with suction nozzle by means of pipelines with non-return valves. The drawing schematically shows the described piston vacuum pump. The pump contains a working cylinder 1 with a piston 2, which divides the volume of the cylinder into two chambers 3 and 4, and sealing rings 5. The working cylinder has channels 6 for bypassing gas from the dead volumes of both chambers. The pump also contains a spool cylinder 7 with a spool 8 dividing the spool cylinder into the suction 9 and exhaust 10 and And cavities. The suction cavity is connected to the pumped-out volume by nozzle 12, and the exhaust cavities are connected via pipes 13 and 14 and non-return valves 15 and 16. The sealing between the spool cavities is performed by rings 17. The chambers 3 and 4 of the working cylinder are connected to the spool cavities at using channels 18 and 19. Compressed gas exits through exhaust valves 20 and 21. A piston and a spool actuate a crank-connecting rod group consisting of a crankshaft 22, a connecting rod 23, an eccentric 24 and 25 g. 25. The eccentric is seated on the shaft with an angle 90 ° advance of respect to the crank. The pump works as follows. When the piston is moved from the left dead center to the right spool due to the eccentric crank lagging 90 ° from the middle position, it moves in the opposite direction to the piston. At this time, the pumped gas from the intake 9 cavity is supplied to the chamber 3 through the channel 18, and the exhaust 11 cavity and the valve 21 to the atmosphere are emitted from the chamber 4 through the channel 19. When the piston approaches the middle position of the zolotnpk, pushing the gas out of the exhaust 10 cavity through the valve 20, comes to the extreme left position. Upon further movement of the piston to the right dead center, the spool will also start moving to the right dead center.

In the exhaust cavity 10, under the action of a pressure difference, the reverse clan is opened 15 and the process of suction into the cavity begins. When the piston approaches the right dead center, the spool closes the channels 18 and 19, the suction process in chamber 3 stops and gas is transferred to it from the dead volume of chamber 4 through channel 6. Then, when the piston moves from the right dead point to the left, the suction begins in the chamber 4 connected through channel 19 to the suction side, it has a 9-cavity spool, and from chamber 3 through channel 18, exhaust 10, the cavity and valve 20 are pushed into the atmosphere, etc.

As the pressure in the evacuated volume decreases, the amount of gas sucked in by the spool exhaust cavities decreases and repaints when the pressure drop across the check valves is not enough to open them. If a

the gas pressure in the process of pumping out of the closed volume decreases so much that the piston cannot push the gas through the clans 20 and 21 into the atmosphere, then further compression of the gas and its release into the atmosphere is carried out exclusively in the exhaust cavities of the spool cylinder when the spool moves to the dead spots .

Subject invention

Double acting piston vacuum pump with spool gas distribution

auth. St. No. 159925, characterized in that, in order to control the exhaust cavities of the spool cylinder in a single-stage pumping mode, said cavities are connected to the suction inlet via pipelines with non-return valves.