DE2016542A1 - / device with at least one cylinder in which a piston-like body can be moved, the seal between the piston and the cylinder wall being formed by a rolling diaphragm - Google Patents

Description

Dr. Herfeert Scholl

Patent attorney

Applicant: 'N.γ. Philips' G! Oei! A.,. Penfabriekeo

File Na., PHN- 3962.

Registration dated April 6, 1970

N.V. PHILIPS GLOEILAMPENFABRIEKEN, EINDHOVEN / HOLLAND

"Device with at least one cylinder in which a piston-like body is movable, the seal between the piston and cylinder wall through a rolling membrane is formed "

The invention relates to a device with at least one cylinder in which a piston-like body can be moved back and forth is to change the volume of a working space containing a working medium by means of the one side, while the other side of this body delimits a further space in which a compressible medium is present, with between Piston and cylinder wall at least one rolling diaphragm is provided, which separates a first space from a second space separates and over which there is an almost constant pressure difference. Devices of this type are known and are e.g. by hot gas piston engines, cold gas cooling machines, Compressors and the like formed.

009846/1074

BATH ORIGINAL

PHN. 3962.

Bel a device known from the French patent I.326.O63, the first space forms one Part of the work space, while the second space with a support fluid is filled. The rolling diaphragm serves to lure gas away from the working area on the one hand and on the other hand prevent contaminants such as lubricants from entering this space.

The second space, the liquid space, can be supplied with liquid (lubricating oil) by pumping means, a control device ensuring that such an amount of liquid is discharged from the liquid space that the pressure difference on a rolling diaphragm facing the hollow side of the gas space does not reach a certain minimum value below and at a convex side the gas space zuwendenden rolling diaphragm a certain maximum value is not V ^ rschreitet ·

The present invention aims to provide a device of the type mentioned in the opening paragraph, its construction is simpler than that in the French patent specification I.326.O63 published device »

The device according to the invention is thereby

characterized in that between the piston and cylinder wall on the working space side of the rolling diaphragm at least one first seal is provided, which separates the first space from the work space, while the second Raus is also a compressible one Contains medium under a pressure which always differs by an almost constant value from the pressure in the first space

009846/1074 BATH

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is «through the first seal between the first room and The pressure changes occurring in the operation of the device in the working area are not reflected in the first Transfer room · The pressure curve in the first room is thus regardless of the one in the work area.

The second space is here also filled with a compressible medium (gas), the mean pressure of which «if the concave side of the rolling membrane facing the first roughness is, is lower than the mean pressure in the first space. "The other way round," run the convex side of the rolling diaphragm to the first Facing the room, the mean pressure in the second room is higher than that in the first room.

The pressure in the first space always shows a difference from the pressure in the second space. Because it was taken care of will, data as explained below, no pressure changes can occur in either the first or the second space, or since the amplitudes and phases of the pressure changes occurring in these spaces are equal to one another, the pressure in the first room always the same difference from the pressure in the second room Device in which the rolling membrane is not supported by a liquid but by a gas, while for it it is ensured that the gas pressure on one side of the rolling diaphragm is always at a constant value from the gas pressure, whose other side is different *

This device has the great advantage that the aforementioned pumping means and the flow control device do not

009846/1074

PHN. 3962.

more are necessary and thus superfluous, thereby obtaining a very simple and inexpensive construction of the device will.

In an advantageous embodiment of the device according to the invention, the second space is open Connection with the wider space, while the seal between the piston and cylinder wall is effective over a diameter is, which is so different from the effective diameter of the rolling diaphragm that the volume of the first Changes occurring in the room cause pressure changes in this room that are at least almost the same and in phase with the pressure changes eH π the further, and associated second space, the mean pressure in the first space differs from that in the further and second room.

An effective diameter of the rolling diaphragm should be understood to mean the sealing diameter, the has the same effect as the rolling membrane and is roughly halfway between the diameters of the surfaces that the rolling membrane rolls along.

The side of the piston-like body facing the wider space becomes in the cylinder when this body moves the volume of the further space and thus the pressure in the further and in the second space connected to it in one Change mass, among other things by the effective surface of the mentioned side and by the stroke of the piston-like Body is determined. By appropriately choosing the volume of the first room and by choosing the appropriate diameter, about

009846/1074 BATH

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that the seal is effective, it is achieved that at one certain different pressure levels in the first and in the second space the pressure changes occurring in the last-mentioned space the pressure changes in the first space are almost the same and in phase.

In an advantageous embodiment of the device according to the invention in the form of a hot gas piston machine of the displacement type, the displacement drive rod being guided through the piston and, in addition to the rolling diaphragm between the piston and cylinder wall and separating the first from the second space, at least one further rolling diaphragm between the piston and the displacement driving rod is provided, which separates a third space from a fourth space, at least one second seal is provided between the parts of the piston and the displacement drive rod between the further rolling diaphragm and the working space, which separates the third space from the working space, which third space with the first Room and which fourth room joins the other room are bound, the first and the second seal each being effective over a diameter that deviates from the effective diameter of the rolling diaphragm or the effective diameter of the further rolling diaphragm in such a way that the changes in volume resulting from the movement of the piston and the displacer change in pressure in the first and third room, which cause the ± Ea further Hatoa xmd ± n the associated second and fourth clearers on teetaadsm pressure changes at least almost equally wad equal wad s ± nd _s where the mean pressure in the first and third room of

00 98 46/107 4.

PHN. 3962.

which differs in the second and fourth room.

The ones in the wider room and those associated with it

second and fourth spaces occurring pressure changes as a result of the movements of the piston-like body and the displacement drive rod which parts move with a certain phase difference are thus determined in the first and in the third Pressure changes occurring at a pressure level in the second and fourth space different from the pressure level in the room first and third room compensated. With adequate volumes of the first and third room and their (their) connecting channel (Channels) and with a suitably chosen diameter of the effect of the seals between the first and the The third room and the working room will always have an almost constant pressure difference across the rolling diaphragms.

Another advantageous embodiment of the Device according to the invention is characterized in that that between the parts of the piston and cylinder wall lying between the rolling diaphragm and the wider space, at least one Third seal is provided, which separates the second space from the further space, the first and the third Seals are effective over the same diameter as the effective diameter of the rolling diaphragm.

The changes in pressure that occur in the wider space when the piston-like body moves are made here no longer in the second room as a result of the third seal palpable · As both the first and the third seal over a diameter equal to the effective diameter of the

0098Λ 6/1 07Λ

BAD ORfQINAL

PHN. 3962.

Rolling diaphragms are effective, remain when the piston moves in the cylinder the volumes of the first and third spaces are almost constant. There are thus almost none in these rooms Changes in pressure, so that the pressure level in the first room differs from that in the second room, via the rolling diaphragm an almost constant pressure difference prevails.

Another advantageous embodiment of the

Device according to the invention in the form of a hot gas piston j | displacer-type machine, the displacer drive rod is guided by the piston and apart from the rolling diaphragm between the piston and cylinder wall, which the first space against the separates the second space, there is at least one further rolling diaphragm between the piston and displacement drive rod, which separating a third space from a fourth space is characterized in that between the parts of the piston and the displacer drive rod between the further rolling diaphragm and at least one second seal is provided in the working space, which seals the third space against the working space separates, with between the parts of the piston and the displacement drive rod between the further rolling diaphragm and the further space there is at least a fourth seal that separates the fourth space from the further space, wherein the first and third seals are effective over the same effective diameter as the rolling diaphragm and the second and fourth seals are effective over the same diameter as the further rolling diaphragm.

The pressure changes occurring in the work area

0098Λ6 / 107Λ

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during the movement of the piston and the displacer in the cylinder due to the presence of the first or second seal, are not noticeable either in the first or in the third room. The pressure changes occurring in the wider space with reciprocal movement of the piston and the displacement rod in the cylinder to the second or fourth space allowed through due to the presence of the third or fourth waterproofing. Furthermore, since the first and second seals are effective over a diameter equal to that effective diameter of the rolling diaphragm, while the third and fourth seals are effective over a diameter are equal to the effective diameter of the further roll membrane is, the volumes of the first, second, third and fourth space remain with reciprocal movement of the piston the displacement rod in the cylinder constant.

There are therefore none in the rooms mentioned

Pressure changes so that both the rolling diaphragm and the further rolling diaphragm always have a constant pressure difference experienced at the constant but different pressure levels in the first and second or in the third and fourth Space.

In a further advantageous embodiment the device according to the invention, the first space is in open communication with the third space and the second Room with the fourth room. This has the advantage that if there are any slight changes in pressure in one of the rooms, e.g. as a result of Dimensional inaccuracies of the components (tolerances), these

0098Λ6 / 107Α BATH

PHN. 39 ^ 2.

Changes in pressure in the larger total volume of the room in where the slight changes in pressure occur and the associated space is compensated for.

Another advantageous embodiment of the Device according to the invention is characterized in that the further space is provided by an airtight crankcase is formed in "in which a with the piston-like body (or piston-like body and displacer) connected f Engine and a generator or electric motor coupled to it are housed.

The device, designed in the form of a hot gas engine, which connects to the engine in the crankcase contains coupled generator, the electrical lines connected to the generator through the ¥ and of the crankcase are brought out, is ideally suited to be independent during a long, uninterrupted period efficient generator of electrical energy to be effective, thanks to the greatly simplified construction of the device Maintenance is hardly or not at all necessary.

If in the crankcase in the form of a cold gas cooling machine trained device according to the invention an electric motor is arranged, a unit is obtained, which can be easily transported and any desired freedom in the arrangement of e.g. measuring equipment in laboratories results in low-temperature investigations.

In a further advantageous embodiment of the device according to the invention are the seals

009846/1074

BATHROOM: QBHQINAt *

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formed by piston rings, each in a groove in the wall of the piston or cylinder or in the displacement drive rod are housed, with an open connection between the space in the relevant groove behind the piston ring and one of the two spaces located on each side of the piston ring and adjoining them is present.

When there is an uninterrupted open connection between the space in the groove behind the piston ring and the working space or the further space is available, since the piston ring seal allows an unhindered gas flow in Direction of the working space or the further space allowed during operation of the device in the space between the rolling diaphragm and piston ring set a mean pressure that is lower than that occurring in the working space or in the wider space, mean pressure and the minimum pressure occurring in this space.

Venn however an open connection between the space in the groove behind the piston ring and the space between If the rolling diaphragm and piston ring are present, the mean pressure that is established in the latter space is due to the piston ring seal a gas flow in the other direction allowed, be higher than that in the working space or in the further The mean pressure occurring in the room and approximately equal to the maximum pressure in the room in question.

Setting a mean pressure in the first space that exceeds the mean pressure in the work space desirable e.g. in the case where the rolling diaphragm is used as a

009846/1074

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seal between the piston and cylinder of a compressor with a suction pressure less than atmospheric pressure. Setting a mean pressure in the first space that is below the mean pressure in the working space is advantageous if the second space is in open connection with the other space, so that a lower pressure level is sufficient in the second and in the further space with a certain pressure difference on the rolling diaphragm . _Λ

The open connection can be established, for example, by opening the piston ring with radial grooves a side facing one of the spaces separated from one another by the piston ring is provided 'or that in the piston or cylinder or in the displacement drive rod a bore is provided.

In a further advantageous embodiment of the device according to the invention, the seals are formed by narrow gaps. The pressure changes in the working area or in another room are allowed to pass through these gaps not · \ to the spaces between the rolling membranes and the columns. Only gas leakage occurs, so that when the device is in operation, a mean pressure will be set in the spaces adjacent to the rolling diaphragm, which will be at least almost the same as the mean pressure occurring in the working space or in the further space.

Another advantageous embodiment of the Device according to the invention is characterized in that that the compressible medium in the second, fourth and

0098A6 / 1Q7Ä

PHN. 3962.

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further room is the same as in the work room.

In a further, advantageous embodiment the device according to the invention, a channel is provided, which is on the one hand on the work space and on the other hand the other room connects and in which one if necessary spring-loaded check valve is housed, which opens in the direction of the space to which the concave side (s) of the Ro3lmombrane (s) is (are) facing.

In practice there will always be some diffusion

through the rolling diaphragm from one side (with the higher pressure, the concave side) to the other side (with the lower Pressure, the convex side). If the concave side of the rolling diaphragm faces the working area, then The medium leaks from the working area into the other room or if the convex side of the rolling diaphragm faces the working area is, Modium is transferred from the wider room to the work room diffuse. In the course of time, a leveling takes place the pressure level in the working space and in the wider space, which can result in the pressure difference on the rolling diaphragm is too low, so that the rolling diaphragm can be damaged by the formation of wrinkles.

With suitably selected initial pressures in the work area and in the further room or in the top and bottom The spaces adjoining the rolling diaphragms can then be opened in a simple manner by means of the channel with the check valve the medium that flows from the room with the higher pressure level through the rolling diaphragm into the room with the lower pressure level

009846/1074

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is diffused, return to the first-mentioned space.

The pressure change occurring in the working space or the other space is used. After diffusion of medium from the high pressure space in the low pressure space can during a certain fraction of a period of pressure be higher in the low-pressure chamber than the pressure occurring at the same time in the high-pressure chamber. During this fraction of the

Period, medium can thus flow back through the check valve from the low-pressure chamber into the high-pressure chamber, so that the original pressure difference at the rolling diaphragm is restored.

The invention is explained in more detail with reference to the drawing explains, for example, some embodiments of Devices with rolling membrane seals schematically and not to scale. Show it:

Fig. 1 shows in section a device with a

a gas-supported rolling diaphragm seal, where the ί

Space inside the rolling diaphragm by means of a piston ring seal is separated from the work area,

1a shows the pressure curve in the different rooms of this device,

2 shows a section through a hot gas motor of the displacement type with rolling membrane seals with gas support, where the spaces within the two Roilmerabranen are characterized by i

Piston ring seals are separated from the working space;

Fig. 3 shows in section a device with a Rolling membrane seal with gas support, with the space above

009846710 * 4

BATH ORIGINAL.

PHN. 3962.

halfway or below the rolling diaphragm by means of a piston ring seal is separated from the work room or the other room,

Fig. K shows in section a hot gas engine of the displacement type with gas-supported rolling diaphragm seals, the spaces within the two rolling diaphragms being separated from the working space by piston ring seals, while the space bordering the lower side of the rolling diaphragms is separated from the crankcase by piston ring seals.

In Fig. 1, 1 denotes a cylinder in which

a piston 2 is movable, the upper side of which can change the volume of a working space 3 in which the working medium is present. The piston 2 is connected to a drive mechanism (not shown) by a piston rod k and has an annular surface 9 on the underside Space 7 separates in which a compressible medium (gas) is present at a mean pressure which is lower than the mean pressure in space 6, so that the concave side of the rolling membrane 5 faces the space 6. A piston ring 8 is also located in a groove in the piston wall between the piston and cylinder walls and separates the working space 3 from the space 6.

Furthermore, a return line 31 is provided, which adjoins the work space 3 on the one hand and space 7 on the other. This line contains a spring-loaded

009846/1074

ORIGINAL BATHROOM.

PHN. 3962

tetes check valve 32, which is in the direction of the work space 3 opens. The piston ring 8 is provided with radial grooves on the underside. This ensures that that there is always an open connection between the space in the groove behind the piston ring and the space 6, so that when the device is in operation, the working medium will leak essentially from the working space 3 into the space 6. As a result, a mean pressure is established in space 6, f which is approximately equal to the maximum pressure occurring in working space 3 will be the same.

This can be advantageous, e.g. with compressors, if the medium at atmospheric pressure is sucked into the working space will.

Venn to be used in this case, a rolling diaphragm with its concave side facing the working space, so it is necessary to back up a stretched position of the rolling diaphragm, a directed to the space 7 Druckunter- _Λ difference of several atmospheres, for example, 5 atm. maintain. If, in contrast to the construction according to FIG. 6, the space 6 is in open connection with the working space, the rolling diaphragm experiences a pressure in the working space at a certain moment which is lower than the desired pressure difference on the rolling diaphragm. If the pressure in the working area is reduced further, the rolling diaphragm does not remain in the desired, stretched position. This difficulty is completely eliminated here by the above-described setting of the maximum pressure occurring in work space 3 in space 6.

009846/1074 BAD ORIQINAt -

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The maximum pressure can be adjusted as follows:

When the pressure in the working space 3 exceeds that in the space 6, the piston ring 8 with its underside pressed against the lower surface of the groove. However, it can then always work medium from the working space 3 through the radial Grooves on the underside of the piston ring 8 flow into the space 6. However, if the pressure in the work area decreases and falls below it he the pressure in space 6, the piston ring reaches the upper surface of the groove with its upper side, so that it the working space 3 seals with the exception of a small leakage. As a result, the mean pressure in space 6 will exceed the mean pressure in working space 3 and will be approximately the same the maximum pressure in this room.

The open connection between the space in the groove behind the piston ring 8 and the space 6 can also be applied to others Way, e.g. by providing a bore in the piston.

The piston ring 8 is on an effective

Diameter D .., which is greater than the effective diameter the rolling diaphragm 5,

If the piston 2 moves down over a distance y, the rolling diaphragm sinks down over a distance of 1/2 y on average.

The space 7 then undergoes a RXING Volumenverringe-, almost equal χ y S, where S is the surface area of the annular surface of the piston 9 denotes second

009846/1074

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Since the effective diameter of the piston ring seal 8 is larger than the effective diameter of the roll membrane, the space 6 also experiences a volume reduction during the downward movement of the piston 2 over the distance y

This volume reduction is:

Ϊ ft - »I)? - Vfe - ° §) ('"*) - J (» ι - "ST-- ³ -

where D denotes the outside diameter of the gap holding the rolling membrane and D denotes the inside diameter. When the piston 2 moves downward, an increase in pressure occurs both in space 7 and in space 6 as a result of the reduction in volume. Conversely, an upward movement of the piston brings about an increase in volume of the spaces 6 and 7 and a decrease in pressure in them.

The pressure level in the chamber 6 is higher enough than that in the space 7 · By suitable choice of the nominal volume of the space 6 and the effective diameter of the piston ring 8 is then ER- Λ that the pressure changes generated during the movement of the piston in the cylinder in the space 6 the Changes in pressure in space 7 are the same and are in phase with these. An at least almost constant pressure difference will therefore also prevail over the rolling diaphragm per stroke.

In practice, there is always a certain diffusion of medium from the space 6 with the higher, mean pressure through the rolling membrane into the space 7 ^with the lower, mean pressure. Medium disappearing from the space 6 is replaced by the medium from the working space 3 on the above

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described way supplemented. After a certain time, such an amount of medium can pass through from the working space 3 and the space 6 the rolling diaphragm must have diffused into space 7 so that the pressure difference on the rolling diaphragm becomes impermissibly low and the membrane can be damaged by the formation of wrinkles. Through the return line 31 with the check valve Medium can be returned from the room 7 to the work room 3 if the nominal pressure levels in these two rooms are selected appropriately. This is explained in more detail with reference to FIG. 1a. Here, ρ denotes the pressure curve in the working area

3 during a period; the curves for p show two different ones Pressure settings in room 7

The pressure in space 7 is for the pressure in the work space 3 out of phase. The pressure level in room 7 is lower than in the work room. The maximum pressure occurring in this space is equal to the minimum pressure in the working space 3 and when the device is in operation, these pressure values occur simultaneously.

The pressure curve ρ in space 6 is with respect to

Phase and amplitude equal to that in space 7 »during the pressure level is approximately the same as the maximum pressure in working space 3 as a result of the described effect of the piston ring 8.

If medium diffusion occurs from the working space 3 and from the space 6 through the rolling diaphragm into the space 7, so that the If the pressure level in the working space 3 drops and that in the space 7 becomes higher, the Kux ^ ven p ^ and p, in the vicinity of the

a D

Intersect point A, p. is then currently higher than ρ, so

There

that medium through the check valve 32 from the space 7 in

0098A6 / 107A

PHN. 3962.

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the work area 3 can be led back. The check valve 32 is arranged in such a way that there is only medium from Room 7 in the direction of work room 3 lets through.

In Fig * la illustrates the full curve of p. the position in which the check valve 32 is not loaded by a spring, so that the pressure in the space 7 can never exceed that of the working space 3. The pressure difference on the rolling diaphragm is then of the Grössenordiiung of the difference g between the maximum and minimum pressures in the working chamber 3 'can be relatively large in certain circumstances. If a lower pressure difference is to prevail on the rolling diaphragm, the check valve can be loaded by a spring, as shown in FIG corresponds to the counter pressure exerted by the spring. The resulting pressure curve in space 7 is indicated in Fig. 1a by a dashed line. I.

In the device obtained in this way, there is always a constant pressure difference across the rolling diaphragm during operation before without the usual liquid sabstützungen of the rolling diaphragm, pumping means and control device in known devices. So although the incompressible liquid support by supporting the Rollmerabrane by means of

a compressible medium is replaced according to the invention, Nevertheless, thanks to the aforementioned measures, it is ensured that the rolling diaphragm is not subjected to any changes in length

00-9846 / 1074

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and thus has a long service life.

Fig. 2 shows in section a hot gas engine; for the items corresponding to those of FIG. 1 are the the same reference numbers are used.

A piston 2 and a displacer 10 can be moved in a cylinder 1.

The piston 2 changes through its upper

Area the volume of a compression space 11, while the displacer 10 changes the volume of an expansion space 12 with its upper side. These two spaces are connected to one another by a cooler 13, a regenerator 14 and a heater 15 and are filled with working medium. The piston 2 is fastened to a yoke 16 by a hollow piston rod k , while the displacer 10 is fastened to a yoke 18 by a displacement rod 17 which is guided through the piston 2 and the hollow piston rod k. The yokes 16 and 18 form part of a rhombus engine 19, which is housed in the space 7 designed as a crankcase, in which. Working medium is also available.

Between the cylinder 1 and the piston 2 there is a rolling diaphragm 5 which separates the space 6 from the space 7 separates. Furthermore, a rolling diaphragm 20 is provided between the piston 2 and the displacement rod 17, which has a space

21 separates from room 7 * Room 6 is through a canal

22 in open connection with room 21. The rolling diaphragms ensure that the working medium is removed from the compression room cannot get into the crankcase 7 and, conversely, impurities such as Schmiej oil from the crankcase 7 cannot

■ PHN. 3962.

- 21 -

Compression space 11 can reach.

Between the piston and cylinder wall or piston

and a piston ring 8 or 23 is provided on the displacer rod wall, which are each accommodated in a groove in the piston wall ". These piston rings separate the spaces 6 and 21 from the Compression room 11.

The piston rings 8 and 23 are provided with radial grooves on the underside. This ensures that there is always an open connection between the spaces in the grooves behind the piston rings and spaces 6 and 21, so that gas leakage will essentially occur from compression space 11 into spaces 6 and 21 during operation. As a result, a mean pressure is established in the spaces 6 and 21 which is higher than the mean pressure occurring in the compression space 11 and is approximately equal to the maximum pressure in the compression space. When the device is in operation, the piston 2 moves with the piston rod k and the displacer ΊΟ moves with a certain phase difference in the cylinder 1.

The extent of the resulting change in volume in space 7 is essentially determined by the surface of the annular surface 9 of the piston 2 and determined by the stroke length of the piston.

In addition, there are still slight changes in volume due to the movement of the piston and displacer rods caused by the surfaces of the undersides of these rods and determined by the relevant lay lengths of these rods

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will. The change in volume caused by the displacer rod has a different size and phase than the change due to the piston piston rod combination.

The summation of these volume changes results in a specific course of the volume of the space 7 and thus a certain pressure curve of the medium in this space, in which the mean pressure level is lower than the mean Pressure level in rooms 6 and 21,

By suitable choice of the volume of the spaces 6 and 2 1 and the effective diameter of the piston rings 8 and 23 is now achieved that at the certain pressure levels these spaces during the movement of the piston and the displacer a pressure curve occurs in the cylinder which is always different by a constant value from the pressure curve in space 7 » The pressure changes in the two spaces are thus the same and in phase with each other, due to the rolling diaphragms 5 and 20 diffused medium is restored in the same way as with the device of FIG. 1 through the control valve 32 in the Compression chamber 11 returned.

FIG. 3 shows a device which broadly corresponds to the device shown in FIG. 1; Corresponding items are given the same reference numbers designated.

In addition to the piston ring 8, which separates the space 6 from the working space 3, this device also contains a piston ring Zh _t which separates a space 25 from the space 7.

The piston rings 8 and Zh both have an effective

009846/10 7 Λ

2018542

PHN. 3962 *

~ 23 - ■

seed diameter equal; the effective diameter of the RoIlrwembraiie 5 * Be the "movement" of the piston 2 in the cylinder T, the volume of the space 6 and that of the space 25 remains constant, so that no pressure changes due to volume changes occur in these spaces, while the pressure changes in the working space 3 and iro space 7 are not transferred from the piston rings 8 or Zk to space 6 or 25. A nearly constant pressure difference will therefore always prevail per stroke via the roller diaphragm the check valve 32 is returned to the working chamber 3.

FIG. K shows an embodiment of a hot gas motor of the displacement type, which broadly corresponds to the device according to FIG. 2, so that corresponding reference numerals are used.

In addition to the piston rings 8 and 23, which separate the spaces 6 and 21 from the compression space 11, a piston ring Z6 is provided between the piston and cylinder walls, which separates a space 27 under the rolling diaphragm 5 from the space 7, while a piston ring 28 is present between the piston and displacer wall, which separates a space 29 under the rolling diaphragm 20 from space 7 «

The piston rings 8 and 26 are «pictures over the

same diameter effective as the rolling diaphragm 5 * during the piston rings 23 and 28 both operate over a diameter equal to the effective diameter of the rolling diaphragm 20 is. This means that with mutual movement

0098A6 / 107 / »

PHN. 3962.

of the piston and the cylinder or the displacer, the volumes of the spaces 6, 21, 7 and 29 remain constant, so that in these No pressure changes occur. The pressure changes in the compression chamber 11 are determined by the piston rings 8 and 23 not allowed to pass through to space 6 or 21, while the pressure changes in space 7 do not penetrate into space 27 or 29 can, since they are held back by the piston rings 26 and 28 ..

The result is that both sides of the rolling diaphragm always have constant but different pressures prevalence. The rooms 6 and 21 are connected by a channel 22, while the rooms 27 and 29 by a Channel 30 are in open communication with each other. this has the advantage that if small changes in pressure would nevertheless occur in one of the rooms during operation of the device e.g. due to tolerances of the interacting parts, these pressure changes are compensated for by the room in question is connected to another room.

This device also has a return line 31 with a check valve 32, so that the medium diffused through the roll membranes 5 and 20 in the space 7 is returned to the compression space 11.

Although in the drawing the rolling diaphragms are all shown in a position in which their concave Sides facing the work space or compression space can of course be maintained while maintaining the the same advantages as the rolling diaphragms with their convex ones

00 9 8 ώ 6 / 107A

PHN. 3962. - 25 -

Turn the page to the rooms mentioned.

The drawing also shows the seal between the space that rests against the rolling diaphragm and the Working space or compression space or the further space formed only by a piston ring. It will be evident that this seal can optionally be formed by several piston rings.

It is further specified that the piston ring facing with the side of the rolling diaphragm provided with radial grooves, so that in the case of the rolling diaphragm adjoining space a pressure is set which is approximately equal to the maximum pressure in the other, on the piston ring adjacent. Space is. Of course, the piston ring can also attach in the groove in such a way that the side provided with radial grooves faces away from the rolling diaphragm is. The pressure that is established in the space between the rolling diaphragm and the piston ring is then approximately equal to the minimum pressure in the space adjacent to the side of the piston ring provided with radial grooves.

The open connection between the space in the groove behind the piston ring and one of the two through it The piston ring can also be separated by radial slots or bores in the upper or lower surface of the groove in the Piston or cylinder or displacement wall are formed.

Under certain circumstances, the seal can also through

a narrow gap can be formed, with the mean pressure prevailing in the space between the ί rolling membrane and the seal,

009846/1074

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the one on the other side of the seal in the work space, compression space or another room is available.

From the above it is evident that the invention is an extremely simple construction of a device with rolling diaphragms between the piston and cylinder or rod, with these rolling diaphragms attached to one side a space filled with gas, e.g. border a work space, be supported on the other side by a gas and There is always a constant pressure difference across these rolling diaphragms.

009846/1074

Claims (1)

PATENT CLAIMS: 2 device with at least one cylinder in which the piston-like body can be moved to and fro to vary the volume of a working space containing a working medium by one side, while the other Side of this body delimits a further space in which a compressible medium is present, whereby between piston and at least one rolling membrane is attached to the cylinder wall and separates a first space from a second space over which an almost constant pressure difference prevails, characterized in that between the parts of the piston ■ and cylinder wall, which are located between the roll diaphragm and the working space, at least one first seal is provided which separates the first space from the work space, the second space also having a compressible medium under one Contains pressure which always has an almost constant difference from the pressure in the first space. 2. Apparatus according to claim 1, characterized in that the second space is in open communication with the more space and the seal between the piston and cylinder wall is effective over a diameter that of the effective diameter of the rolling diaphragm deviates in such a way that j the resulting changes in volume of the first space Cause pressure changes in this space that are at least almost the same and in phase with the pressure changes in the further and connected second space, the mean pressure in the first space of that in the further and in the second room deviates. 009846/10 PHN. 3962. - 28 - 3. Device according to claim 2 in the form of a hot gas piston machine of the displacement type wherein the displacement drive rod is guided through the piston and, in addition to the rolling diaphragm between the piston and cylinder walls, which separates the first space from the second space, there is at least one further rolling diaphragm between the piston and displacement drive rod, which separates a third from a fourth space, characterized in that between the parts of the piston and the displacement drive rod between the further rolling diaphragm and the working space there is at least one second seal which separates the third space from the working space, the third space with the first space and the fourth space with the other Space are connected and wherein the first and the second seal are each effective over a diameter that deviates from the effective diameter of the rolling diaphragm or from the effective diameter of the further rolling diaphragm in such a way that the volume changes that occur as a result when the piston moves ens and the displacer cause pressure changes in the first and third space that are at least almost the same and in phase with the pressure changes in the further space and the associated second and fourth space, the mean pressure in the first and third space being different from that in the second and deviates in the fourth room. k. Device according to Claim 1, characterized in that at least one third seal is provided between the parts of the piston and cylinder wall lying between the cylinder and the further space, which seal the second space from inside 0Q98A6 / 1 074 BAD ORIGINAL ₍ ^ ₁ PHN. 3962, separates further space, wherein the first and the third seal are effective over a diameter which is equal to the effective diameter of the rolling diaphragm ', 5. Device according to Claim h in the form of a hot gas Kölbenmaschine of the displacement type, wherein the Verdrängertriebstange is executed through the piston and out of the rolling diaphragm between the piston and cylinder wall that separates the ER- g th space from the second space, at least one further rolling diaphragm between the piston and displacement drive rod, which separates a third from a fourth space, characterized in that at least one second seal is provided between the parts of the piston and the displacement drive rod between the further rolling diaphragm and the working space, which seal the third space from the working space separates, wherein between the lying between the further rolling diaphragm and the further space parts of the piston and the displacement drive rod at least one fourth seal is provided, which separates the fourth space from the further space and wherein the first and the third seal over a diameter are effective, the same is the effective diameter of the rolling diaphragm and the second and liierte seal are effective over a diameter which is equal to the effective diameter of the further rolling diaphragm. 6. The device according to claim 5, characterized in that the first space is in open communication with the third . th room and the second room with the fourth room is «i 7. Device naph one or more άβν before- j 009846/1074 BADORJGfNAt * PHN. 3962. - 30 - going claims characterized in that the further Space is formed by an airtight crankcase in which a piston-like body (or piston and displacer) connected engine and a generator or electric motor coupled to it are housed. 8. Device according to one of the preceding claims, characterized in that the seals by Piston rings are formed, each in a groove in the wall of the piston or the cylinder or the displacement drive rod are housed, with an open connection between the space in the associated groove behind the piston ring and one of the two spaces located on each side of the piston ring and adjoining them is present. 9 «Device according to one of claims 1 to 8 characterized in that the seals are formed by narrow gaps. 10. Device according to one of the preceding claims, characterized in that the compressible medium the same medium as the medium in the work area is in the second, fourth and further room. 11. Device according to one of the preceding claims characterized in that a channel connects on the one hand to the work space and on the other hand to the further space and an optionally spring-loaded check valve which opens in the direction of the space to which the hollow side (s) of the rolling diaphragm (s) facing 1st (are), 009846/1074