DE2361068A1 - ROTARY LISTON COMPRESSORS, IN PARTICULAR DRY OR FLOODED SCREW COMPRESSORS - Google Patents

Description

236} 068

DEHA.G Aktiengesellschaft December 5, 1972

M D u is bur g 5757 - Kai./We.

V / olfgang-Reuter-Platz

Rotary piston compressor, especially dry or flooded running screw compressor

The invention relates to a rotary piston compressor, in particular dry or flooded running screw compressor with an axially parallel, intermeshing housing bores that mesh with each other and are axially parallel each other .arrangedem screw rotors pair, the male rotor mainly outside of his Part circle lying screw ribs and its female rotor mainly within its part circle Has lying screw grooves.

In order to achieve the greatest possible effect with compressors of this type To be able to achieve, their gaps must be seen between the double-cylinder Housing wall and the periphery of the rotors be as small as humanly possible. This dimensioning is however thereby a limit is set down that the rotors heat up during operation and consequently on all sides stretch. The rotors are therefore sized outside so that they run free of constraints in the housing at operating temperature.

■ 609825/00

23ol068

5757 - Kai./We. December 5th

It is well known that the ilotors heat up much more on their pressure side than on their suction side. This depends on the pressure difference • Teiaperaturunterscliicd may be carried iji cut with ca .. 20O ⁰ G, namely- K) ° ü on the suction side and 25O ⁰ C on the pressure side. Jm. su prevent a larger air gap remaining on the suction side during operation than on the pressure side, it is known to form both rotors with an outer diameter tapering towards the pressure side. This improves the performance of the compressor somewhat. Depending on the size of the rotors - outside diameter - the larger taper is approx. 0.12 to 0.58 mm.

The invention is based on the object of providing a screw compressor which runs dry or flooded as described in the manner possible; easy and economical way to train in such a way that its performance is still is increased considerably further.

To solve this problem, for a screw compressor with an axially parallel, intersecting one Housing bores meshing with each other and axially parallel to each other arranged screw rotors pair, whose male rotor or main rotor mainly screw ribs lying outside of its pitch circle and its female rotor or idler mainly within having its pitch circle lying screw grooves, according to the invention suggested both rotors or at least one of the two rotors both in its outer diameter and its base diameter as well as in its visual cone profile tapering longitudinally towards the pressure side. Here it is advisable to dilute the basic diameter and the adjacent inner x'rofilb * rich one rotor or both rotors smaller than that of the outer diameter and the adjacent outer profile areas.

509825/0054 SAO ORIGINAL

■ - I'ai. / V / ß. . . ; 5th December 1975

- 3 ■: - ■

In this way, a much better efficiency of the screw compressor is achieved in an extremely simple way, because now not only the 'air gaps between the rotors and the housing bore can be kept extremely small on the suction side, but above all a much better seal on the Profile flattening and at the base diameter in the border area between high pressure and low pressure chambers. is attainable. This increase in output also has the effect, for example, that the rotors can now be considerably shorter with the same output and the compressor can thus be produced considerably more easily and economically. In addition, the considerable reduction in number and size of the air gaps also reduces the temperature difference accordingly, because now less compressed air can penetrate through the remaining gaps and heat the rotors by friction. It then needs for example, only with a temperature difference · voji about to be reckoned 130 ⁰ C instead of the previous 200 ⁰ C. Accordingly, the conicity required according to the invention is also reduced. This is preferably the same or almost the same in all radial areas as the predeterminable amount by which both rotors expand more at operating temperature on the warmer pressure side than on the cooler suction side. "..-_ ■; - ..

Although rotors designed in this way are intended in particular for dry running compressors, they can also be used in flooded running screw compressors for the purpose of increasing performance. ^::

In the drawing is an embodiment of two rotors shown schematically with air gaps that have been enlarged many times, namely?; eigt

9B-257ÜÖ5

- Kai./ie. 5th December 1973

Fig. 1 shows the stretched and approximately fifty times enlarged thickness of the gap between a rotor according to the invention and the housing and

2 shows the same gap profile between a cylindrical rotor and the housing,

Fig. 3 shows the also stretched and with about

fifty times enlarged thickness shown gap course between a hip of an inventive Main rotor and the groove of a secondary rotor according to the invention along the section line III-III in FIGS. 5 and Fig. 6, while

Fig. Λ analogously the same gap course between

shows two conventional runners along the section line III - III in FIG. 5 and FIG

Fig. 5 leaves the growth of the air gap at the

Detect the pressure side by increasing the operating temperature and

'Fig. 6 the growth of the air gap at the suction

side of a trained according to the invention Pair of runners,

In comparison to FIG. 6, FIG. 7 'shows that at operating temperature Large gap thickness of a conventional rotor pair remaining on the suction side.

In all figures, the dash-dotted lines indicate the con-

509825/0054

5757 - Kai./We. 5th December 1973

Doors at room temperature, while the solid lines for the contours that apply at operating temperature are valid. -

In Fig. 1 and 2, the indicated inner jacket of the compressor housing is with. 1 ■ denotes. As FIG. 1 shows, with longitudinally conical rotors 2, the final gap 3 can be kept constant or at least nearly constant thin at operating temperature from the suction side S to the pressure side D. Here, a room temperature of 20 C and an operating temperature on the suction side S is assumed to be vonwenigei * 5O ⁰ O and on the pressure side D of more than 180 ⁰ C. Then the dash-dotted line 4-iait about fifty times enlargement indicates the extremely small but equally effective conicity of the rotor 3.

A conventional rotor 5, on the other hand, has a cylindrical one Outside diameter 6. Since at operating temperature however, the runner 5 on the suction side only expands very slightly, remains almost over the entire length of the runner 5 here a relatively thick gap 7 between the inner jacket 1 and the crown of the ribs.

As can be seen in FIGS. 3 and 4, the difference in the gap thicknesses in the contact zone of the two rotors 10, ΛΛ is still considerably greater, namely twice as much as in the case of the longitudinally conical rotor pair 8, 9-

According to the invention, however, are also the ribs or the Groove flanks or the flanks of both runners 8, 9 as well as the basic diameter of at least the main rotor to the pressure side tapered longitudinally and to a lesser extent than its outer diameter. ' Fig. 5 leaves the gap thickness the print side - again in about fifty times an exaggeration

509825/0054

23610S8

5757 - Kai./We. 5th December 1973

Compare at room and operating temperature. To the same pair of runners 8 ·, 9 belongs to Fig. 6, which the in-'sequence the much smaller temperature difference of approx. 30 C correspondingly lower elongation of these runners on the suction side. As a result of the longitudinally conical formation of the pair of runners 8, .9, however, is now the thief of the gap 3 in the lying on the section line III - III Level extremely small along the entire length of the pair of runners. They are correspondingly small remaining loss «, caused by the overflow of compressed air through tiny gaps into the suction chamber develop"

Finally, FIG. 7 shows in connection with FIG. 4 the low elongation of the conventionally cylindrical rotor pair 10, 11 on the suction side at operating temperature. Despite The thermal expansion of the rotor 10, 11 leaves a very harmful, thick gap 7, which only appears on the pressure side tapers to the same small amount that the gap already has on the suction side.

-BAD ORiQiMAL

50 98 25/005 4

Claims (5)

■ ^ 7 - I) EdAG Aktiengesellschaft December 5, 19? 3 ' D u i s b u r g 5757 - Kai./We. Wolfgang-Reuter-Platz Patent claims Rotary piston compressor, in particular screw compressor running dry or flooded, with a pair of screw rotors which mesh with one another in axially parallel, intersecting housing bores and are arranged axially parallel to one another, the male rotor of which has screw ribs primarily outside its pitch circle and the female rotor of which has screw grooves primarily within its pitch circle, characterized in that: , ■ / '"that both rotors (8, 9) to _{w at} least one of the two rotors (8-) both in its outer diameter and its base diameter (12) and in its screw profile tapered longitudinally towards the pressure side (D) is. 2. Rotary piston compressor according to claim 1, characterized, that the taper of the base diameter (12) and of the adjoining inner profile area of a rotor (8) or of both rotors (8, 9) is smaller than that of the outer diameter and the adjacent outer Profile area. · ■ - · ■ · 'BAD ORiGiNAL 5098 25/005 4 - Kai / We. December 5, 1973 I. 3. Rotary piston compressor according to claims 1 and 2, characterized, that the entire taper is equal, or nearly equal, is the predeterminable degree by which both At operating temperature, the rotors stretch more on the warmer pressure side (D) than on the cooler one Suction side (S). · 6.09825 / 0054