Device for controlling the output of rotary compressors

#1. Field of the Invention

#The invention relates to devices for controlling the output of rotary compressors, which devices have a regulating flap valve and a check valve in a common housing, the regulating flap valve controllably changing the passage cross section of the suction duct of a rotary compressor and the check valve being located behind the regulating flap valve in the direction of flow.

#2. The Prior Art

#FIG. 1 shows a cross section through a preferred embodiment of a device according to the present invention wherein the housing parts are oriented such that the flange connections at its opposite ends extend in parallel with one another,

#FIG. 2 shows the device of FIG. 1 wherein the housing parts are reoriented such that the flange connections at its opposite ends extend perpendicularly to one another, and

#FIG. 3 shows a perspective view of the device of FIG. 1 at a slant angle and from behind.

#The device for controlling the output of rotary compressors shown in FIGS. 1-3 is connected during operation to the inlet port or the suction port of the rotary compressor (not further illustrated). It includes a lower connection flange 1 which is connected to the rotary compressor, with an O-ring inserted in the groove 2. The upper connection flange 3 is joined to the connecting feed line or to a muffler, an air filter or the like (also not further illustrated). To regulate the cross-sectional area of the passage of the suction duct leading through the device, a regulating flap valve 4 is provided, which has a regulating flap 6 that may be pivoted about a pivot pin 5 extending perpendicularly to the plane of FIGS. 1 and 2, and whereby the regulating flap 6 closes the passage cross-section in the illustrated position and which in turn fully opens up to a position indicated by dotted lines in FIG. 1. Additionally, a check valve 7 is located downstream of the regulating flap valve to cooperate with the regulating flap valve in a common housing. The check valve 7 includes a return-kick flap 12 having a counterweight 10 pre-tensioned in the closing direction toward a seat 11 whereby the check valve 7 stops the back-flow of the sealed medium from the compressor side.

#The housing 8 is divided between the two valves 4, 7 in a dividing plane 13 that lies slanted toward the planes A, B of the connection flanges 1, 3 on both sides, and the housing 8 may be assembled with different relative positions of the two housing parts 14, 15 in a manner easily seen in FIGS. 1 through 3. The dividing plane 13 is slanted by 45° in the illustrated embodiment relative to the planes A, B of the connection flanges 1, 3 at both sides, and there are arranged in the area of the dividing plane 13 and outside of the flow cross-section and laterally thereto two guide elements 16, 17 on the two housing parts 14, 15, which are oriented parallel to one another and which permit relative rotation of the two parts by 180° and thereby allow the different relative positions of the housing parts 14, 15 illustrated in FIGS. 1 and 2. It can be ensured thereby in a very simple manner that the illustrated connection of the upper connection flange 3 extends upwardly according to FIG. 1 or to the side according to FIG. 2, which is very advantageous when considering local assembly conditions whereby it does not require any additional connection points that would make the bearing position more complicated and increase the dimensions of the entire arrangement.

#Cooperating recesses and projections 18, 19 (see FIG. 3) are provided on the guide elements 16, 17 to fix the mutual position of the two housing parts 14, 15 whereby preferably pin-type slide-in elements may be inserted between groove-type recesses 20 for mutual fixing of the two housing parts 14, 15 or the cooperating guide elements 16, 17 (not shown here separately).