Vacuum pump system including scroll pump and secondary pumping mechanism

Patent metadata

Field	Value
Publication number	US-2016348679-A1
Application number	US-201514726404-A
Country	US
Kind code	A1
Filing date	May 29, 2015
Priority date	May 29, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

A vacuum pump system includes a secondary pumping mechanism incorporated into a stationary portion of a scroll pump. The stationary portion includes the stationary plate scroll of the scroll pump and defines a gas passageway in which the secondary pumping mechanism is disposed. The gas passageway is connected to a gas flow path through the scroll pump at a location upstream of an exhaust check valve of the scroll pump. The secondary pumping mechanism is displaceable within the gas passageway to draw residual gas in the compression stage upstream of the check valve into the gas passageway, and may pump the residual gas back out through the exhaust check valve, to evacuate residual gas from the compression stage.

First claim

What is claimed is:

1 . A vacuum pump system comprising the combination of a scroll pump, and a secondary pump,
wherein the scroll pump has an inlet opening, an exhaust opening, an outboard section, an orbiting scroll blade, and an exhaust check valve, the outboard section includes a stationary scroll blade and defines a gas passageway therein, the orbiting scroll blade is nested with the stationary scroll blade so as to delimit therewith a series of pockets constituting a compression stage of the scroll pump, the pockets consist of an inlet pocket at which fluid is taken into the compression stage, an outlet pocket at which fluid is discharged from the compression stage, and at least one intermediate pocket between the inlet and outlet pockets with respect to said direction of flow of gas through the compression stage, the exhaust opening is connected to the compression stage at the outlet pocket of the compression stage, and the check valve is disposed in the exhaust opening, and the gas passageway has a first end, and a second end at which the gas passageway is directly connected to a path of gas flow through the scroll pump that starts at the inlet opening, runs through the compression stage and ends at the check valve, and wherein the secondary pump comprises a secondary pumping mechanism operatively associated with said gas passageway of the scroll pump and displaceable to draw gas into the second end of the gas passageway from the gas flow path such that residual gas in the compression stage upstream of the exhaust check valve can be evacuated from the compression stage.

2 . The vacuum pump system of claim 1 , wherein the at least one intermediate pocket comprises a plurality of intermediate pockets in series between the inlet and outlet pockets with respect to said direction of flow of gas through the compression stage, and the second end of the gas passageway is directly connected to one of the intermediate pockets.

3 . The vacuum pump system of claim 1 , wherein the secondary pumping mechanism provides a hermetic seal in said gas passageway between the compression stage and the atmosphere outside the pump system.

4 . The vacuum pump system of claim 1 , wherein the secondary pumping mechanism comprises a piston disposed within said gas passageway.

5 . The vacuum pump system of claim 4 , wherein the piston is magnetic, and wherein the secondary pump comprises a magnetic actuator disposed outside of the gas passageway and operable to reciprocate the piston with the gas passageway.

6 . The vacuum pump system of claim 4 , wherein the secondary pump comprises a thermal actuator that reciprocates the piston with the gas passageway.

7 . The vacuum pump system of claim 4 , wherein the secondary pump further comprises a bellows disposed within the gas passageway, the bellows being fixed to and extending between the piston and to the outboard section of the scroll pump so as to provide a hermetic seal in the gas passageway between the compression stage of the scroll pump and the atmosphere outside the pump system.

8 . The vacuum pump system of claim 1 , wherein the secondary pump comprises an intermittent driver operatively connected to the secondary pumping mechanism so as to drive secondary pumping mechanism intermittently

9 . The vacuum pump system of claim 8 , wherein the intermittent driver comprises a motor, and a controller operatively connected to the motor and configured to operate in a mode in which the motor is run intermittently.

10 . A vacuum pump system comprising:
an inlet at a vacuum side of the pump system where fluid is drawn into the pump system; an outlet constituting a compression side of the pump system where fluid is discharged under pressure from the pump system; and a pump head assembly including: a stationary portion defining an inlet opening to which the pump inlet extends, an exhaust opening leading to the pump outlet, and a gas passageway, and the stationary portion comprising a stationary scroll blade, an orbiting plate scroll comprising an orbiting scroll blade, an eccentric drive mechanism supported by the stationary portion, the orbiting plate scroll being coupled to the eccentric drive mechanism so as to be driven by the eccentric drive mechanism in an orbit relative to the stationary portion, an exhaust check valve supported by the stationary portion and having a valve head seated in the exhaust opening, and a secondary pumping mechanism disposed in the gas passageway, and wherein the stationary and orbiting scroll blades are nested such that a series of pockets are delimited by the nested stationary and orbiting scroll blades, the series of pockets constitute a compression stage of the pump head assembly and consist of an inlet pocket at which fluid is taken into the compression stage, an outlet pocket at which fluid is discharged from the compression stage and at least one intermediate pocket between the inlet and outlet pockets with respect to a direction of flow of fluid through the compression stage, the gas passageway has a first end, and a second end at which the gas passageway is directly connected to a path of gas flow that starts at the inlet opening, runs through the compression stage and ends at the check valve, and the secondary pumping mechanism is displaceable within the gas passageway to draw gas into the second end of the gas passageway such that residual gas in the compression stage upstream of the check valve can be evacuated from the compression stage.

11 . The vacuum pump system of claim 10 , wherein the at least one intermediate pocket comprises a plurality of intermediate pockets defined by and between the nested stationary and orbital scroll blades in series with respect to said direction of flow of gas through the compression stage, and the second end of the gas passageway is directly connected.

12 . The vacuum pump system of claim 10 , wherein the secondary pumping mechanism provides a hermetic seal in said gas passageway between the compression stage and the atmosphere outside the pump system.

13 . The vacuum pump system of claim 10 , wherein the secondary pumping mechanism comprises a piston disposed within said gas passageway.

14 . The vacuum pump system of claim 13 , wherein the piston is magnetic, and further comprising a magnetic actuator disposed outside of the gas passageway and operable to reciprocate the piston with the gas passageway.

15 . The vacuum pump system of claim 13 , further comprising a thermal actuator operable to reciprocate the piston with the gas passageway.

16 . The vacuum pump system of claim 13 , further comprising a bellows disposed within the gas passageway, the bellows being fixed to and extending between the piston and the stationary portion so as to provide a hermetic seal in the gas passageway between the compression stage and the atmosphere outside the pump system.

17 . The vacuum pump system of claim 10 , further comprising an intermittent driver operatively connected to the secondary pumping mechanism so as to drive secondary pumping mechanism intermittently

18 . The vacuum pump system of claim 17 , wherein the intermittent driver comprises a motor, and a controller operatively connected to the motor and configured to operate in a mode in which the motor is run intermittently.

19 . A vacuum pump system comprising:
a stationary portion defining an inlet opening, a gas passageway, and an exhaust opening, and the stationary portion comprising a stationary scroll blade; an orbiting scroll blade

Assignees

• Agilent Technologies Inc

Inventors

• Forni Ronald J

Classifications

• F04B41/06 Primary

  Combinations of two or more pumps · CPC title

• F04C27/02 Primary

  Liquid sealing for high-vacuum pumps {or for compressors} · CPC title

• F04B43/02

  having plate-like flexible members, e.g. diaphragms (F04B43/14 takes precedence) · CPC title

• F04C18/0223

  with symmetrical double wraps · CPC title

• F04C23/006

  having complementary function · CPC title