DE2364727A1 - Adjacent-disc rotor or housing for screw rotary piston engine - has tapered slotted discs to compensate thermal expansion - Google Patents

Abstract

Rotor or housing of axially adjacent discs for screw rotary engines with units for operation at high temps. has the discs tapered, in dependence on their coefficients of expansion and a measured or calculated isothermal field from the region of the coolant openings to their periphery, in thickness, and pref. slotted at 90 deg. to the field of isotherms, such that at max. working temp. the taper and slot opening are exactly compensated. Preferably there may be parting gaps in an angle deviating from 90 deg. to the disc surface, instead of the slots; the disc thickness in the region of the gaps is reduced on the diametrically opposite sides of the discs. Warping of the discs owing to thermal expansion is prevented, and heat dissipation is improved.

Description

for screw-type rotary piston machines.

The invention relates to rotors or housings made of axially juxtaposed discs for rotary piston machines, Especially for screw-type rotary piston machines with Facilities for operation at high temperatures,

Such rotors and housings composed of disks for rotary piston machines and the arrangement of cooling channels in these parts are known from German Patent No. 91 ^ · 886. There are also arrangements for cooling of housings and rotors for V ore aub endr ehko Ib enma chinen, especially for high gas temperatures, also from the American Patent No. 2,808,813 is known.

However, the results obtained with the arrangements and cooling devices according to the proposals in the aforementioned patents were not satisfactory, so that until recently there have been further proposals in this direction, for example according to American Patent No. 3,405,6ok for veil and boundary layer cooling on screw-type rotary piston machines were made. To date, however, the disruptive housing and rotary piston distortions have not been satisfactorily reduced or even eliminated, especially when such rotary piston or screw rotary piston machines are to be operated as prime movers with similar or higher temperatures, as are common in gas turbines.

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The invention is based on the object in such Rotors or housings made of disks arranged axially next to one another cause warping due to thermal expansion avoid and improve heat dissipation.

To solve this problem it is provided according to the invention, that the, slices depending on their extensibility efficient and one by measurement or calculation determined isothermal field, from the area of the coolant openings are tapered in the slice thickness up to their periphery and preferably perpendicular to the * Isothermal field are slotted in such a way that the taper and the slot opening at the maximum working temperature are just compensated.

Another 'embodiment of the invention is that instead of the slots, parting lines are provided at an angle deviating from the perpendicular to the pane surface and that the pane thickness in the area of the parting line on the diametrically opposite sides of the discs is reduced.

To influence the thermal expansion is dit> invention furthermore designed so that the disks are equipped with openings for a coolant flow and these coolant openings in one or more disc or discs arranged next to one another are spatially offset.

In a simple manner, the coolant flow, in particular when used on rotors, can be handled in such a way that for the coolant supply and removal through channels in the Shaft in each case at least one of the disks with at least one coolant opening extended towards the shaft is provided.

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In this way, rotary piston machines !! and screwdriver ehkolbenmas cMnen according to the aforementioned patents and according to German Patent No. 1 751 091 for at least the same or even significantly higher working temperatures than usually advantageous for gas turbines applicable. -

The application of the measures according to the invention in conjunction with the construction, in particular of rotors made of disks or Sheet metal enables the production of large machines with, for example, rotor diameters of more than 1 meter in a simpler way than before.

The subject of the invention is based on the drawings explained. Show it

Figure 1 shows a longitudinal section through a rotor made of axially juxtaposed discs for a rotary piston or Screwdriver piston machine up to the center line of the Wave corresponding to line I - I in Pigur 2 and FIG. 2 shows a view of a device designed according to the invention Disc, for example the main rotor of a screwdriving piston machine with sketched isotherm field and indicated coolant holes for in the axial direction arranged further disks, as well as FIG. 3 a detail of the top view of the periphery a disc with a parting line.

The rotor half shown in cross section in FIG. 1 with the shaft 1, the coaxial coolant supply opening 2 and the coolant discharge opening 3 furthermore shows the disks 4 to 15 which are arranged axially next to one another and which can also have different thicknesses from one another. The disks h and 15 represent end schexfoen, the disks 5 and 14 have enlarged coolant openings 10 and 17 towards the shaft liin so that the coolant is supplied through a channel and discharged through a channel 19 after the disks have passed through. The openings or holes 20 and 21 in 'the disks 6 to

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are spatially offset in such a way that the flowing through them Coolant is diverted several times. The disks 4 to 15 are conical on their periphery, tapered, as indicated by reference number 22.

Figure 2 shows the plan view of the disk 4 according to Figure 1 and the ¥ elle 1 with the coolant supply opening 2 and the channel 18. The disk 5 behind it »that of rotary piston machines by one given by the pitch of the screw profiles Angle is offset, with the enlarged coolant opening 16 is in connection with the further behind lying disc 6 with the outlined coolant openings or bores 20 and continue with the subsequent disk 7 with the coolant openings or holes 21. The path of the coolant is on this Way ensured uninterrupted over the disks 10 to 13 up to the coolant discharge opening 3. In the slices 4 to 15 slots 23 are attached. Cut-out the isotherm 28 for a higher and the isotherm for a lower temperature are shown, while the maximum working temperature at the periphery 30 prevails.

Figure 3 shows a portion 25 of the periphery of the Disk 4, in which a parting line 24 in one of the Perpendicular to the Seheiberi surface deviating angle 26 is arranged. The thickness of the disk 4 is diametrically opposite in the area of the parting line Digits 27 decreased.

The mode of action is as follows:

That into the shaft 1 via the coolant supply opening 2 Inflowing gaseous or liquid coolant reaches the coolant openings 16, 20 via the channel 18, the disks of the rotor of a rotary piston machine, shown here in simplified form. The coolant is inside of the disks 5 to 14 by the staggered Openings 20 and 21 deflected several times, so that a

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turbulent flow results. The offset arranged openings or holes 20, 21 results in an enlarged heat transfer surface compared to otherwise usual, aligned aligned openings and bores with the same diameter. In this way, the heat transfer from the disks 5 to 14 to the coolant is increased compared to the usual arrangements . The coolant runs off via the opening 17, the channel 19 and the shaft bore 3, the diameter of which is advantageously greater than that of the shaft bore 2. The disks. h to 15 can optionally be glued, welded, riveted or connected by bolts. The connection to the shaft can also be made detachable or non-detachable. In large machines, the disks can also be composed of segments. The thickness of the pane to be selected depends both on manufacturing aspects and on the heat transfer of the respective material. Practical values are between 0.1 and 10 mm. However, the subject matter of the invention is not limited to these values.

If, for example, Invar steels were available for a large temperature range, theoretically no consideration of the coefficient of thermal expansion would be necessary for the panes. With regard to price and ease of processing, materials, in particular sheets or metal disks, are used today, which have a strongly noticeable coefficient of thermal expansion. For this reason, the disks k 1 to 15 advantageously have conical tapers 22 which are established on the basis of measurements or calculations of an isothermal field 28, 29.

The tapers 22 are chosen so that after Setting the maximum working temperature at the periphery 30 through the thermal expansions of these tapers. are just re-compensated. Furthermore are the slots 23 due to the expansion coefficient of the used

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Discs and the Isothermenfeldes 28, 29 so too dimension, ■ that their wedge-shaped opening also at maximum 'steady-state temperature at the periphery 30 is being compensated. In this way it turns out to be Operation with the working temperature in both axial and a closed surface also in the circumferential direction. The number and position of the slots 23 must be taken into account the mechanical strength of the panes can be selected as required.

The function of the proposed slots can also be fulfilled by obliquely arranged parting lines that the Material of the pane under the influence of thermal stresses offer lateral evasions. By diminishing the slice thickness at the points 27, the lateral evasive movement receives enough leeway so that at maximum Working temperature the pane next to it is not disturbed.

The application is not limited to the simplified Example of a rotor for rotary piston machines limited, but is also applicable to the housing parts. Furthermore, the explanations apply not only to straight-toothed but Also for helical rotary lobes, especially for screw end caps.

Because the thermal expansions are not only in the axial direction and, as before, in the radial direction, but now also have the possibility according to the invention in the circumferential direction So far, they have been observed to appear three-dimensionally free Warping even at high temperatures, i.e. 1000 C. and more, avoided.

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The invention can be applied particularly advantageously to reddening piston internal combustion engines applied with screw rotary piston according to German Patent No. 1 751 091 because, due to the isothermal expansion possible there for all disks of a rotary piston, the thermal Loads evenly in terms of the working process are.

K claims
3 figures

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Claims (4)

Claims Μ.! Rotors or housings from axially arranged side by side Disks for rotary piston machines, in particular for screw rotary piston machines with facilities for operation at high temperatures, characterized in that the discs depending on their expansion coefficient and one isothermal field determined by measurement or calculation from the area of the coolant openings to their periphery are tapered in the disk thickness in such a way and preferably are slotted perpendicular to the isothermal field in such a way that at the maximum working temperature the taper and the slot opening are just compensated. 2. rotors or housing according to claim 1, characterized characterized in that instead of the slots parting lines in one deviating from the perpendicular to the pane surface Angle are provided and that the slice thickness is in the range the parting line on the diametrically opposite sides of the discs is reduced. 3. rotors or housing according to claim 1 or 2, characterized in that the disks for a coolant flow are equipped with openings and these coolant openings are arranged in one or more side by side Disc or discs are spatially offset. 4. Rotors according to one of the preceding claims, characterized in that for the Kühlniittelzufuhjr and -Discharge through channels in the shaft at least one of the disks is provided with at least one coolant opening extended up to the shaft. 5 0 98 27/0105 Blank page