GB2278649A

GB2278649A - Rotary piston machines

Info

Publication number: GB2278649A
Application number: GB9410011A
Authority: GB
Inventors: Wolfhart Willimczik
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-05-20
Filing date: 1994-05-18
Publication date: 1994-12-07
Anticipated expiration: 2014-05-18
Also published as: CA2123933A1; GB9410011D0; DE4411383A1; GB2278649B

Description

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This application is related to a second continuation-in-part of application, "Kinematic assembly for wear-resistant transmission of forces upon conversion of motions, especially a stroke motion into a rotational motion," US- serial number 07/493,901, filed March 15, 1990, abandoned, and is related to the first continuation-in-part application, "Rotary piston machine with a wear-resistant driving mechanism," serial number 07/832,381, filed on February 7, 1992 in the U.S. Patent and Trademark Office.

The original application, "KolberLmaschine mit formschliissigen Kraftiibertragungsteilen" or "Piston machine with desmodromically guided parts" No. P 39 08 744.1, was filed March 17, 1989 in the German Patent Office.

2 BACKGROUND OF THE INVENTION

This invention relates generally to a rotary assembly device that converts fluid or gas power directly into rotating mechanical force, and vice versa, without any corotating bearings in the rotating power train or actuating mechanism; and particularly, to rotary piston machines with bearingless, direct or desmodromically guided power transmission parts, and hydrostatic pressure compensated or balanced stressless sliding parts. Each cooperating cylinder and piston pair forms a pressure tight work chamber. Both piston and cylinder are moved along different, but closely neighboring orbits. This enables a short stroke motion between both, the piston and the cylinder, in a co-rotating body-bounded-system. Such a reciprocative movement between a piston and cylinder caused no oscillating mass power because it exists in a co-rotating system only. The slortness (compared with a diameter of an orbit) of the stroke motion is not a disadvantage. Pistons are directly and fluidly, but never via bearings, attached to a piston carrier. Pistons, piston rods, and a piston carrier are the main parts of a piston rotor. The cylinders are integrated in a compact contiguous cylinder rotor and are irterengaged by the pistons and both rotors are rotational coupled thereof. The configuration in space of both rotor axes is basically arbitrary, but must lie within all orbits. The direction in space of the stroke motion is freely selectable. Consequently, the axial and radial machines are only corner stones in this field.

This kind of positive displacement machine is characterized by 3 the absence of any bearing in the power train or actuating mechanism to transmit the piston force. Consequently, this principle is able to run absolutely oil-free as a pump or as a water-hydraulic-motor, it can generate oil-free and highly compressed air. It operates as a compressor or vacuum PUMP,, or a combination thereof, sealing and cooling.

An additional balancing of the movable parts makes the sliding between the sliding parts stressless. Consequently, this principle is able to work, such as in the aforementioned machines, not only oil-free, but also, and simultaneously, at hig'li pressure (over 100 bar), at high performances and at high efficiency; for instance as a water hydraulic motor or a high pressure water pump, whereby other parameters, like delivery, are practically unlimited.

with or without water as system fluid for DESCRIPTION OF THE PRIOR ART

An earlier invention, No. P 39 08 744.1, filed March 17, 1989 in the German Patent Office, describes a new design for a power/ torque transmission, and in particular for rotary piston machines.

A piston and a cooperating cylinder rotate in two slightly different, closely neighboring, and near-circularly orbits. This difference generates an oscillation between each piston and cylinder pairs in a corotating, body-bounded system. One component of this oscillation, the component along the cylinder axis, creates a useful short-stroke motion in a rotating, body-bounded system. According to cylindrical coordinates, a component, ver- 4 tical to the first one and in any direction, remains. This component is first minimized and then compensated without using bearings. This was the basic task.

The pistons, the piston rods, and the piston carrier are combined to- form a piston rotor without the use of bearings between the pistons and the drive shaft. The piston rotor is mostly rigidly fixed on a driving shaft. The pistons interengage the cylinders which are integrated in a compact cylinder drum or cylinder rotor, which has at least one cylinder. The cylinder rotor slides with one surface, including the open ends or openings of the cylinders, and adjacent the control surface, upon a alwas stationary control surface. The control surface can be in any given rotational symmetrical shape, preferably even, conical and cylindrical. The angle between the drive shaft and the cylinder symmetry axes is unlimited variable, that is, any angle between 0' and 3600 is possible. Consequently, axial (small angles) and radial (90') machines are included as corner stones in this field.

A bearing-free actuating mechanism has been created for basically all rotary piston machines. This invention has eliminated all ordinary corotating bearings, exposed to the media, within the machine. This has been the scope of the original invention.

Such piston principle is pressure tight. Therefore, these facts would make the whole scale of rotary piston machines simpler and able to run oil-free, if there would not be other obstacles like too much stress on flexible power transmitting parts and too much friction on sliding parts caused by a high pressure within the machine. The well-known problem of too much contact pressure appears at a high pressure. Consequently, a nonlubricating fluid R like water would generate too much wear, but today's needs for oil-free machines are increasing; examples include compressors.. non-flammable hydraulic systems, in particular, a water hydraulic motor.

The new contiguous power train would not only applicable for every wellknown machine, but also for every unknown rotary piston machine, because the idea is based on fundamental physical facts, which has been never considered in regard to rotary piston machines. This was simultaneoUsly the reason for any number of examples.

SUMMARY OF THE INVENTION

The present invention relates to a rotary piston machine with direct or desmodromically guided parts in the piston actuating mechanism, that is actually a bearing-free power train, and solves the aforementioned problems. This iivention creates a very strong actuating mechanism without using bearings and reduces friction significantly by a pressure compensation of all sliding parts at high pressure. Therefore, this invention creates very powerful positive displacement machines which can operate at high volume, high pressure, and high performance with a high efficiency and after all, which are able to operate without lubrication.

The above and further objects of the invention will become obvious to those skilled in the art and in theoretical mechanics upon reading the following description.

The main parts of the actuating mechanism of this machine are a piston rotor and a cylinder rotor which included a number of 6 pistons, piston seals, piston rods, piston carriers and mostly a shaft and sometimes another piston rotor and at least one cylinder rotor with at least one cylinder. The cylinders are integrated in a compact uninterrupted cylinder rotor. All these parts -can be lateral shiftable to solve the problem caused by the inclination between both rotors.

The theoretical base for this invention was found in the characteristic of the cosine function around 0 which describes the ratio between gaining a useful work chamber volume and the increase of unwanted disparities in dependence of the inclination angle or distance between both rotors. The changing of the cosine function around 0 is insignificant, and therefore, the displacements are such insignificant too (only a small fraction of the entire stroke length) that bearings are not more necessary if a short stroke length is applied. The desirable result is, here are only lateral shiftable elements in the actuating mechanism instead of bearings. This allows to use strong piston connecting members to build a very strong (perhaps the strongest at all) piston actuating mechanism.

The idea was, to equalize the disparities without using bearings; or in other words, to move the piston seal along the cylinder wall in spite of the fact that the piston attempts to leave the cylinder center line and to move on a deformed arc. The solution was as follows: every circular or arched movement can be decomposed into two linear movements, each being vertical to one another. In case of an exact circular movement, the amplitudes are even for both components. But in the case, the circular motion is only an arched oscillation within 100 (+/-5'), instead of 3600, one component of the movement is only about 1% 7 of the other. A short arc is almost a straight line. The physics shows, every disparity comes into being by the cosine function (or 1 - cos x) of the inclination angle and the distance between both axes, respectively. The cosine function has only very small changes around W, for instance between 0 and S' only about as much as between 10' and 110; that is, between 50 around 00 as much as for only 10 at an angle around 110. (cos 50 - cos 00 = cos 11.2 - cos 1C; 0.996 - 1 = 0.9809 -0.9848). (Ordinary axial piston machines operate at higher angles and generate a lot of disparities which must be compensated by bearings.) In other words, it must be possible, to create a volume fot a displacemet machine almost without displacements between pistons and cylinders if only small angles or distances between the rotor axes are used. These inventions are technical applications of the characteristic of the cosine function around 00. Therefore, the remaining disparities or deflections crosswise to the stroke motion can be easily eliminated without using bearings. The deflections and the necessary shifts are only in the order of magnitude of 1% of a relative short stroke length. The normal clearance in a thread or the clearance between other engaged parts, for instance between the pistons and the piston sealing elements, lateral to the stroke motion, or the natural or a priori elasticity of piston rods, even screws in steel, provide already enough space for the remaining deviations or deflections.

In the case of an axial machine and according to cylindrical coordinates, the deflections between the pistons and the cylinders can be decomposed in a first radial component and in a second circumferential component. First, tw circles with the 8 same diameter in space, but slantways to each other, are elliptically distorted to each other. Therefore, the radial distance or diameter between two opposite pistons and the concerning cylinders is not always equal within one rotation. The difference is the radial conponent of the deviations. Second, the pistons and the cylinders are normally exactly circularly arranged having a constant angle-distance between two neighboring elements. This angle is in respect to the other rotor variable through one revolution and being dependable at the inclination angle between both rotors. A slanted'projection of any angle shows an other angle. An angle is basically covariant in regard of any transformation of coordinates. There is only one exception, an angle of 180' which is actually a strait line. We experience that a shadow of a strait line on a plain is always a strait line again. This is the reason that between two opposite pistons or cylinders a minimum of the displacements exists and such two-cylinder machine has advantages.

A greater inclination angle would require the use of real elastic material or other solutions, but a greater angle for a greater volume is not necessary, because the volume of the cylinder increases with the square of the radius, and the inclination angle changes only the length of the stroke motion. Therefore, it is more effective to change the diameters of the pistons and the cylinders, and the divided circumference (bolt circle) for a greater volume of the machine which is actually a simple photographic enlargement of the machine. Any volume and delivery are possible.

The physics delivers a theory that the cylinder rotor doesn't need selfguiding parts like a shaft, because it is guided by 2 9 the pistons and piston seals respectively. This seems to be c. contradiction because all piston seals can be loose around the p-:st(,;, rod. Actually, not all ston seals guide the cylinder rotor simultaneously. The theory of this guiding mechanism is complicated and can not be described here in full. One important result is that all lateral movable parts find the best position automaticly for a minimum of all lateral deviations ergo shifts. A proper construction creates a smooth rotation of all movable parts even at high performances. Practice has shown that indeed the piston rotor starts to move on a polygon shaped distorted circle, with a number of corners corresponding to the nimber of pistons, instead of a circle, if all lateral mobilities together are unnecessary to great.

Another problem is the wear problem at high pressure altitudes, at high volume and with non-lubricating fluids, such as water. This problem is solved by a quasi complete pressure release of 71 all movable parts and, in particular, between sliding parts. The physics shows the way. Friction, and consequently wear, being dependable on sliding speed, material conditions, and increases linear with the contact pressure. A high contact pressure rust be removed or minimized by pressure balancing every single movable part; that is, the elimination of every burdensome contact pressure between every touching sliding components, or in other words, by making the sum of all attached force vectors on every movable part equal zero in order to achieve a complete force equalization or balance. The balance is ideal if a necessary sealing pressure remains only and consequently both sliding partners are sliding without stress. All movable parts rotate only. These rotating parts include a compact uninterrupted cy- -0 linder rotor and a fluidly summarized piston rotor, mostly attached to a drive shaft. ( When two or more formations of pistons and cylinders are being used for different tasks in the same housing, for example, a motor and a pump, an outgoing shaft and shaft seal are not necessary.) The physical logical guide line, to solve this prementioned problem, is as follows: to eliminate wear by high pressure, friction must be eliminated. To eliminate friction, contact pressure must be eliminated. To eliminate contact pressure, forces between sliding parts must be eliminated. To eliminate forces, a force equalization must be achieved for every movable pa'rt.

The deciding parameters are the hydraulic forces caused by fluid or gas pressure. There are basically three pressure levels, namely: the input level, the output level, and the pressure level in the housing of the machine, which can be variably selected to help solve the problem. Another variable parameter is the size of each sealed pressurized area having a certain pressure level, and particularly, two areas with an opposite direction of the force vectors. On both rotors, there are, or will be created, different sealed pressurized areas or pressure cushions with contrary directions of the force vectors in order to balance both movable parts. The sum of all forces can be made almost equal to zero for both rotors by using a suitable configuration and likewise, for axial and radial machines. In addition, the rotational connection between both rotors can be made substantially torque free.

Balancing of the piston rotor:

The pistons, actually the piston rods, can basically push, pull, 11 or both with different selectable amounts during one revolution. In the case of a radial piston machine, there are no axial forces.

The radial forces can be balanced by two or more neighboring circles of circularly arranged cylinders in the same cylinder rotor. Both systems work separately against the same pressure level but are rotated 1800 against each other. Consequently, the radial forces are counter balanced regardless as to whether the pistons are pulling or pushing.

In the case of an axial piston machiqe different options are possible for an axial balance of the piston rotor, inclUaing the outgoin6 drive shaft.

The first option is as follows: the pistons experience a pressure difference only during on half of one revolution, only over one half of the stationary control plane, that is, a semi-circle on the suction or low pressure half, that is, a stationary working side. Consequently, the piston sealing elements have to be pressure-tight only for one half of one revolution, and only in one direction, like a simple wiper. The compression stage in the cylinder is eliminated. Instead, the pistons have to pull during the induction stage against the pressure in the pressurized housing on the backside of the pistons. Now, the piston rotor and the drive shaft can be balanced in a simple manner. The sealed area of the shaft seal must be equal to the sum of all crosssections of the pistons just over the working side, or low pressure half. The axial force vectors on the pistons and on the shaft are oppositely directed. The pressurized areas must be equiareal, that is, must have the same area content. In this content, the sealed shaft can be considered as an larger addi- 12 tional piston pulling in a opposite direction. The pulsations are minimized by using an suitable number of pistons, and suitable control periods. It is to be noted this new working process has a useful side effect. The compression stage in the cylinder, usually following after a suction stage, is practically eliminated; in fact, it has a zero pressure difference, because, during this stage, the same pressure is on both sides of a piston. Fluid will be ejected out the cylinder only. This is a significant advantage because all well-known disadvantages of a compression stage are eliminated as well. For example, no piston machine is able to pump a fluid-gas mixture to high pressure due to pressure shock waves in the cylinder during the compression stage. This is the reason why the entire air conditioning industry is still using compressors instead of simpler and smaller fluid-pumps.

The axial machine can be balanced in absence of a shaft seal also. (If there is on both axial ends a shaft, there is no need for a balance because it is a priori balenced). The pistons, just being over the suction side, can pull and, over the pressure side, push the same amount of force, but in opposite directions, so that the sum of all force vectors is equal zero. In this case both halves, the high and the low pressure half, respectively, are sealed and are working sides. The pistons and the respective sealing elements are pressure-tight in both directions and in the housing is about half delivery pressure.

A combination of both options is possible too: for example, for large machines having piston cross-sections much wider than the cross-section of a sealed drive shaft. The pressure in the housing will be a little greater than one-half the delivery pressu- 13 re, and the pistons pull on the suction side more than the pistons push on the pressure side. (In this content the sealed shaft can be considered as an additional piston.) To this end, the sum of the axial force vectors will be zero.

In case of two axial opposite directed piston rotors or opposite directed piston rods on a piston carrier and two cylinder rotors in one housing, the axial balancing is very simple; the piston forces must be equalized only.

These balancing concepts work regardless whether the sealing element wipes against the cylinder or against the piston plunger.

Balancing of the cylinder rotor:

A problem appears at high pressure, an ordinary cylinder rotor would be pressed to much against the control surface, in particular, in a low pressure area of a control surface by a high pressure in the housing and in absence of any lubrication.

Around any low pressure channel in the control plate exist a low pressure area or cushion which sucks the cylinder rotor against the control plate. Actually, the high pressure in the housing presses the cylinder rotor against the control surface because the counter force is missing over a low pressure channel.

Goal is, to make the sum off all forces, attached on the cylinder rotor, almost zero or, in other words, to create certain high pressure cushions between both sliding parts for a complete hydrostatic pressure compensation of the cylinder rotor against the stationary control plate.

The generally way is always the same: create enough high pressure cushions, preferably direct in a former low pressure zone, to 14 release the cylinder rotor from burdensome contact pressure against the control plate.

Such low pressure areas are the cross sections or bottoms of the cylinders being just connected via the openings to a low pressure channel. Therefore, the bottoms of the cylinders adjacent to the control plate must be partly closed and -chis closed portion underneath each cylinder must be sealed against low pressure in the rotating openings and in the stationary channel to retain a high pressure cushion around a low pressure area. Actually, it is a reduction of the size of the low pressure area and an enlargement of the size of the high pressure area between the cylinder rotor and the control surface in the stationary low pressure half until the cylinder rotor is in balance. This is, if the size of the low pressure area is equal to the sum of the cross sections of all non-pressurized cylinders. A pressurized cushion under a cylinder has no counter-force on the cylinder rotor because this portion of the pressure field hangs on the pistons and further on the piston rotor instead on the cylinder rotor. Therefore, the pressure cushions can be adjusted to any specific construction, such as; axial or radial machines; pulling and/or pushing pistons or better piston rods; a pressurized housing or not; an outgoing shaft or not; etc. Furthermore this concept is applicable to any numbers of cylinders in any configuration and at any pressure.

In the case, there is only one high pressure level, the delivery high pressure in the housing, then, two areas with the same area content but with a opposite direction of the force vector would be enough to balance or pressure compensate the said rotor.

in case of an axial piston machine, the cylinder rotor being a disk with two circularly faces, an upper face and a lower face adjacent to the control surface, called control face, containing the bottoms of the cylinders with the openings. The cylinder rotor rotates sealingly on the staying control surface. Thereby, the cylinders experience different stationary pressure levels, over on half of the control plate high pressure, that is the high pressure half, and over the low pressure alf low pressure, that is the low pressure half or side of the control surface.

Presupposed the pistons are working only during the time over the low pressure half of the control surface and the piston rods are pulling only, one "stationary half" of a rotating disc shaped cylinder rotor, that is, the half just being over the high pressure side of the control surface, is a priori in balance because there is everywhere, that is, on both opposite faces and in the cylinders, the same pressure, that is, the high pressure of the housing.

Over the stationary low pressure half are a number of cylinders just connected with a low,pressure channel-and ergo low pressure in the concerned cylinders.

The cylinder rotor being axial in balance, if the amount of the forces on both faces are equal and the force vector opposite directed, or in other words, the contents of the low pressure areas on both circularly faces must be equal, or that is, a low pressure cushion around the low pressure control channel must have the same size as all cylinders together which are just connected to the low pressure channel.

For an equal area content, the radial extension of the sealed area must be narrower (The extension in peripheral direction being predetermined by the control mechanism and can not be 16 changed without consequences which are difficult to describe) than the diameter of the cylinders; and therefore, the cylinders must be partly closed and the remaining openings must be sealed against high pressure which comes now underneath the cylinders. These pressure cushions generates a force away from the control surface. Therefore, the cylinder rotor being now in balance if the pressure cushions have a proper size. In practice the force equalization is made, that a small amount contact pressure remains, to generate the necessary sealing pressure.

For instance, if there is an six cylinder axial piston machine and 3 of the cylinders are in time over the low pressu:re half, the cylinder rotor being balanced, if the size of the stationary sealed low pressure area around the low pressure channel underneath the cylinder rotor is equal to the size of three cylinder cross-sections. Or the same condition in other words: The suction side is balanced if the sealed and covered area under each cylinder is equiareal to the sealed area between two neighboricylinders. If the sizes of both areas are equal, the amount of the two force vectors are equal too, and they have opposing directions; therefore, the sum of all fluid forces is equal zero.

Practice has shown this method is so effective that, in spite of high pressure in the housing, the cylinder rotor can actually lift off from the control surface. Every desired sealing contact pressure is adjustable regardless of all other'parameters.

On the pressure half, balance is not necessary if there is not a compression stage. If there is a compression stage and the pistons are pushing too, both sides, the low and high pressure halves, are working sides. On the high pressure half, the size 17 of the sealing area or high pressure cushion must be different for a separate pressure balance of both halves. This can be done by changing the profile of the control surface. This profile can be different on both halves, therefore, the low and the high pressure halves can be balanced separately.

These balance concepts are basically applicable for any configuration of a radial or axial piston machine, and regardless whether the control surface is a level plane, a cylinder jacket, a cone jacket, and the like.

In axial piston machines, the openings in the bottoms of the cylinders are mostly more inside. But it is advantageous for large Compressors, if using water as a sealing fluid, to make a second opening on the outside and use each opening for a separate inlet or respective outlet, because the water is already preseparated from the air in the work chamber by radial forces.

Balancing of the pistons in a transversal direction and, in particular, between both rotors in a circumferential direction:

This balancing provides a quasi torque free connection between both rotors and a relief of the sealing elements between cylinders and pistons from lateral or transversal forces, which come into being by three different reasons. The first reason, concerning the axial machines only, is related to the displacements or disparities between the pistons and the cylinders due to the inclination between both rotor axes. Circularly arranged formations of pistons and cylinders, slantways to each other, appear elliptical distorted relative to each other. There are many ways to solve the problem due to the deviations between the orbits of 1 18 the pistons and the cylinders perpendicular to the stroke motion. This concerns the following parts: the piston carrier, the attachment of the piston rod to the piston carrier, the piston rod, the piston, the piston seal, the cylinder, the attachment of the cylinder on the cylinder rotor, and the cylinder rotor. All these parts or the connections between them can be made loose or flexible, but always for small amplitudes or angles only.(Loosely connected or attached is defined as fixed in a longitudinal or force direction, and in a lateral or perpendicular direction loosely or with a certain clearance, for instance, like an attachment of a turbine blade.) Each item-dlone can basically solve this problem, at least to an inclination angle of 5. In practice, several items may work together, even at greater angles.

The performance of this machine will not be deteriorate by the above. On the other hand, pumps for a low performance, in a range up to 10 bar only, can be made very simple in rubber and plastic parts. The piston and piston rod.can be made together, in one piece, like a plastic screw with a head like a spherical sealing element, etc.

In practice, the following items have already proven to be ef- fective for at least a water pressure of 100 bar: a radial clearance between piston and piston seal, a flexible piston seal, a loosely threaded piston rod in a piston carrier, and a flexible piston rod.

The second reason for a balance in a circumferential direction is related to the friction between the cylinder rotor and the stationary control surface. This is already solved by pressure balancing the cylinder rotor against the control surface. (The 1 19 friction, caused directly by the fluid in the housing-is insignificant. ) The third reason is caused by a transversal or lateral fluid pressure due to a deviation from the rotational symmetry of the sealing line between piston and cylinder, for instance, by using a simple wiper in the cylinder due to its inclined position. This causes an asymmetrical or non- rotational symmetrical pressure field around the cylinder wall due to a slanted circular or slightly elliptic sealing line from a non-spherical piston seal against the cylinder wall. This generates lateral forces in a peripheral direction and ergo a torque. The surface-notmal-vector oi the sealing plane is not in the axis of symmetry of the cylinder. Its movement describes a cone-shaped surface with the same inclination angle as between both rotor axes but around the axis of symmetry of the cylinder. The component in peripheral direction swings in a sinusoidal variation. This usually generates a torque in the wrong direction of rotation. In the case a simple wiper is used as a piston seal, the cylinder rotor would be a performance part. In special applications, it can be useful. But it can be changed by changing a built-in inclination angle of the circular sealing element to compensate partly for the inclination angle on the working side. A specific angle cannot only significantly reduce the hydraulic forces in a circumferential direction, but also generate a hydraulic force in a direction of turning. The proper angle reduces torque between both the cylinder and the piston rotors and relieves the sealing elements from burdensome lateral forces. Here is described a driven machine like a pump.. The optimal angle for the best possible balance is for a water-hydraulic-moto slightly smaller.

A specific amount of tangential hydraulic force, to overcome the friction, must be in the opposite tangential direction because of the reverse direction of rotation of a motor compared with a pump. The optimal angle can be achieved by a slanted sealing element, a slanted attachment between piston and sealing part, or by a bent piston rod, or by a slanted or tilted attachment between a straight piston rod and the piston carrier, like a swept-back piston rod in reference to the moving direction, ergo in circumference direction. In the last version, the tractive force vector for each piston rod is in the symmetry axis of the piston rod, and swings only a little sinusoidally. Or,in other words, when the sealing element has to provide a pressure tightness for the pressure difference on the working side, its position in the cylinder is straightened.

This balancing procedure is so effective that the piston rods of a water hydraulic motor could have the properties of a rope. In reality, the piston rods could be made partly of properties like a rope when the pistons are pulling only. A rope moves automatically in the direction of the resulting force vector and simultaneously, it relieves each sealing element most completely from lateral forces. Therefore, the piston rods don't need a lateral stability and they form self-aligned the optimal swept-back angle. (A slanted cylinder in a cylinder rotor would have the same effect but also displays a negative side effect.) A reduction of the inclination on the suction side causes a larger inclination on the pressure side. It would be harder for the sealing elements, specifically a wiper, to provide a proper sealing quality but there is no need for a pressure tightness or sealing properties.

1 21 This applies to simple wipers. in practice, spherical piston seals are more often used. By using a spherical piston or piston seal, the sealing line shifts around the ball and is never inclined with respect to the cylinder. The surface-normal-vector of the sealing plane (all points of the sealing line lie in this plane) remains along the axis of symmetry of the cylinder, ergo, no lateral forces on the cylinder walls are generated by fluid pressure, ergo, the cylinder rotor is not a performance part.

If there is one turning direction only, partly spherical wipers and strait piston rods, actually screws, are attached via threads at an small tangentially incline to the piston'carrier, ergo swept-back with respect to the moving direction. In this case, the cylinder rotor is torque free, ergo the spherical piston seals and the swept-back piston rods are released from lateral forces also. Tangentially forces appear on the piston carrier only, ergo the swept-back piston rods generate the useful torque direct on a shaft and without generating a burdensome lateral force somewhere.

In the event that a sealing element is located on top of the cylinder and wipes along a piston plunger, there is a priori (naturally) no torque on the cylinder rotor because the plane defined by the sealing line or by the corresponding surface-normal-vector is always straight to the cylinder and it is not a performance part. At least a number of the sealing elements can be flexible and slightly shiftable laterally.

For a simple pump, it can be enough, if at least the entire top of the cylinder rotor is made of a flexible material. The elastic circular edge of the cylindrical bore with the sealing ability also provides a certain shift ability, and/or the piston 1 22 plungers are laterally loose and/or flexible. In the case of an axial machine, the later mentioned distance bolt or spacer pin between both rotors can be rotationally coupled at both ends and used as a small driving shaft or torsion wire fn order to transmit torque to the cylinder rotor to overcome the remaining friction, and/or a spring can be used, which is rotationally coupled to both rotors and preloaded in a turning direction.

In a radial piston machine, slanted piston rods, even ropes are not exactly radial directed but in a direction of the present force vector; the piston rods end on an inner circle where they generati torque directly upon the piston rotor and shaft, respectively.

In accordance with these details for a balancing in a transversal and, in particular, in a circumferential direction, it must not be forgotten that the greatest amount of reduction of all transversal forces or sh ifts is made by the reduction of the inclination angle between both rotors; that is, the remarkable low changing characteristics of the cosine function around 00. Small angles of about 5 are used. Machines with an inclination angle over 10' would demand much more.effort to compensate the disparities.

Balancing the piston rods in longitudinal direction:

More displacement volume will not be achieved by an unlimited increase in the inclination angle, but will be achieved by an unlimited enlargement of the diameters of the pistons, simply by an photographic enlargement 'f the machine. An extreme high Y 23 -1 piston force may causes that high tractive force on a relative slender piston rod that even steel may pull off or breakup; but even this can be balanced too.

Each piston rod must be sealingly surrounded or jacketed by a flexible pressure-tight material like hard rubber, in a largest possible diameter. Because of the inclination, the diameter must be a little smaller than the diameter of the cylinders.

This effect is similar to that of the piston plungers. This opens up the way to high performances and large machines according to the present invention while retaining flexibility of a thin piston rod.

All oi this is possible but not necessary; a solid and stiff piston rod can always be used at any desired performance.

Piston plungers are in no danger to pull off, because there is no tractive force on the plungers. If the plungers are sealingly attached to the pis-Con carrier; the piston force is only on the piston carrier.

Balancing without pressure:

To balance this machine in absence of pressure, for example, when initially starting the machine, a special fastening means is necessary to hold the cylinder rotor slidingly on the control surface, but only in the case of an axial piston machine. The cylinder rotor has the tendency to lift off from the lower part I of the control plane and to straitens up, ergo to reduce the inclination angle to zero. A spacer pin is positioned between both rotors in the center line of the piston rotor to hold the cylinder rotor against the control plane. The spacer pin or pivot bears swingable in a spherical hole in the cylinder rotor 24 in a point of intersection between both rotor axes, and axially in a middle plane of the stroke motion. A remaining axial clearance would cause a leakage gap between the control plane and the cylinder rotor, but this gap will be removed by using a compression spring around the spacer pin or by using other springy or resilient devices, which push the cylinder rotor against the control plane at a predetermined force. One end of the compression spring presses against the piston rotor or piston carrier or drive shaft and the opposite end of the spring presses against the cylinder rotor or a step of the spacer pin and the spacer pin presses against the cylinder rotor.

The strength of the spring must substantially overcome the frictional forces of the pistons in the cylinders in the absence of any system pressure. The weight of the cylinder rotor may help to generate this force. The friction of the sealing elements is made as low as possible. This ensures that a machine, such as a pump. can run dry without noticeably heating up maintaining a good suction capability.

Balancing of the shaft seal:

It is well known that a mechanic shaft seal needs a larger shaft diameter on the rotating part of a seal foe balancing at high pressure. This necessary wider shaft may provide a husk or sleeve on the backside of the piston rotor. The rotating part of the shaft seal can be mounted directly on an end of the piston rotor with a diameter suitable to achieve a proper balance between two adjacent sealing rings and can be driven by drive dogs on the end of the husk.

The diameter of the husk and the diameter of the shaft seal can be made in any size which may balance the cylinder rotor in axial direction.

Balancing in presence of foreign particles:

A special device is necessary to prevent damage to a machine due to incoming foreign particles that may cause a devostating high point contact pressure. This may result in demolishing the machine. A theoretical solution is to remove the possibility of too high amounts of a contact pressure. A practicable solution is an application of such sliding parts which are only loaded by a spring, or by fluid-pressure.

In case of an axial machine, this concept is easily to use for a sliding area between a cylinder rotor and a control plate. A cylinder rotor is held on the control plate only by fluid pressure and a compression spring. In this case the spacer pin is removed or replaced by a suitable devise. When a foreign particle comes into this area, the cylinder rotor will lift-off and come down again when the particle is through the machine.

Another matter of concern is with respect to the frictional relationship between the piston and the cylinder. A soft sealing element has to remain on the cylinder wall and would scratch the cylinder wall if a sharp and hard foreign particle stick on i t. But this can be prevented, at least for only pulling piston rods, by using a retaining-spring as a holding device in an axial or longitudinal direction for a sealing element on the piston head. The spring is just strong enough to overcome a normal friction between the sealing-element and the cylinder wall. If a particle blocks the axial movement of the sealing element, the spring will be periodically compressed and the sea- 26 ling element will not execute the full stroke motion or no stroke motion relative to the cylinder untill the foreign particle is no longer present.

Both applications -of this concept together make the machine robust and durable against the impact of foreign particles.

Now, in view of the foregoing discussion, this rotary piston machine has a unique quality that every movable part is balanced or counterbalanced, including the drive shaft. Nowhere in this machine exist a burdensome contact pressure in spite of high pressure within the machine. The friction is minimized, even at high pressure, high speed, and large volu. mes. Many versions and combinations of these machines are possible. This principle is characterized by the largest range of variable parameters like pressure, displacement volume, speed, performance and others.

Without any fluid, the friction can be minimized so significant ly that machines, such as pumps, can permanently run dry without noticable warming and retaining a good suction capability. Con ventional axial piston pumps already have the best efficiency, but this invention will improve the efficiency even without using oil. There exists not only high pressure water pumps in a range of several kilowatt but olso a very small three-cylinder pump with an electric capacity of less than 10 watt and a deli very of less than 1 liter/min and after all, this pump has, dry running, a suction capability of several meters.

The above described concepts are applicable not only to axial or radial rotary piston machines, or between them, but also for all desired variable parameters, such as displacement volume, pressure, or performance, and fluid parameters. This machine is invented and developed, in particular, for media without a lu- 27 bricating ability, like oil-free air and clean water. Examples are: permanently dry running pumps without valves but with an unique suction ability, even by smallest possible displacement volumes; high pressure water pumps for every volume; water hydraulic motors for every performance; vacuum pumps; oil-free compressors for high pressure; air motors; engines; metering pumps; special pumps for a gas-fluid mixture; and others. There is also a whole scale of combinations of the versions, for instance, a water hydraulic motor, driven by any fluid under pressure, for energy recovery systems, in particular, for the reverse osmosis. A high percentage of the sea water at a pressure of about 70 bar (1000 PSI) comes out the drain of the reverse osmosis system and this energy is wasted in today's systems. A water hydraulic motor according to this invention can be connected to the drain and drive a pump to feed the same or another system with fresh sea water without additional energy costs. The same procedure can be repeated until almost the whole amount of pressure water is transformed in drinking water. The electrical counterpart or pendant of such machine would be a transformer or motor generator unit. An axial piston pump and a motor can be attached to the same shaft. The same formations of the same pistons are contrary directed. The inclination angle and the delivery is for the pump a little smaller compared with the motor with it the pump is able to generate a higher pressure than the motor is running with to feed the same system with fresh sea water. Sizes for millions of Liters per day are possible. This concept lowers the energy costs for the reverse osmosis so drastically that everyone on this planet can get enough drinking water in a high quality. An other example is an air 28 compressor, driven by a water hydraulic motor wherein the water can be replaced by any other non-abrasive fluid. This system works for submersible applications too, for instance, to bring compressed-air in waters like oxygen lost lakes. The air is mixed with water under high pressure, this raises the efficiency of today's methods significantly. On the other hand, this pump is a compressor with a system fluid generatingan extremely high air pressure in one stage.

Usually, the required delivery pressure by compressors is not so high and a pressure compensation for the sliding parts not so decisive. Therefore, the cylinder rotor can be guided by its own shaft or stub shaft without special bearings and the cylinders can almost be closed on the bottoms. In the case of axial machines this allows a significant reduction of the control device to a small interior area having the lowest sliding speed. This is advantageously by using large cylinders.

71 In the case of an axial compressor or engine, there is a special way to reduce or eliminate the disparities between the pistons and cylinders by the inclination between both rotors.

The cylinder axes are bent, as part of a great circle, around an imaginary globe with the center of the globe in a point of intersection of both axes. This eliminates said radial deflections between the pistons and cylinders. The deflections of a two cylinder machine with two oppositely arranged and arched cylinders and spherical pistons are exactly zero, ergo no shifts are necessary; likewise, for one cylinder machines. Each of the rotors can be made in one piece and totally rigid. Therefore, such a machine is suitable for very high speed, large displacement volumes, and a greater angle between the rotors too. The 29 sliding speed is relative low and no mass power exists. The channel control devise can be very close to the axis of the cylinder rotor or valves can be used instead.

The applications of this invention for gas as a media are not only a compressor or an air motor with or without water as an operating or system fluid for sealing and cooling in the housing, but are also applicable for an engine. One unit works as a compressor to feed a combustion chamber and after it, the second modified machine works like an air motor for hot gas. Both units can be mounted on the same shaft or can be rotationally coupled by gear wheels or the like. All parts can be cooled y the operating fluid. Here, oil can be used for cooling and lubricating. In this case, the pistons need oil rings. Said version with a spherical piston, surrounded by a cylindrical sealing element, is suitable. With this engine, it is possible to combine the relative low speed of a classical piston engine and a continuous burning of a turbine. It can be called "Displacement Turbine".

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a partially sectional, elevational view of an axial- pistonmachine in accordance with the present invention; Fig. la shows a partially broken plan view of a control plate with a cylinder rotor shown partially in full; Fig. 2 shows a partially broken plan view of a cylinder rotor with a control plate shown in full; Fig. 3 shows a partially sectional, partial elevational view of a piston in a cylinder and a slanted sealing element or wiper; Fig. 4 shows a partially sectional, partial elevational view of a piston with a spherical piston ring; Fig. 5 is a partial elevational view of a piston shaped like a spherical bearing and a partial sectional, elevational view of a cylinder; Fig. 6 shows a partial elevational view of a piston plunger with a wiper and cylinder; Fig. 7 is a partially sectional, elevational view of an axial-pistonmachine with piston plungers; Fig. 8 is a partial sectional, elevational view of a soft piston plunger, and a hard cylinder; Fig. 9 shows a partially sectional, elevational view another version of rotors for an axial-piston-machine; Fig. 9a shows an elevational view of a piston of Fig. 9 partly in section and enlarged so as to show detail; Fig. 10a shows a partial plane view of another version of a piston attached to a piston carrier; Fig. 10b shows an elevational view of the piston shown in Fig. 10a partly in section and attached to the piston carrier; Fig. 11 is a partially sectional, elevational view of another piston attached to a piston carrier; Fig. 12 shows a partially sectional, partial elevational view of a pushing piston with a piston seal; Fig. 13 shows a sectional, elevational view of a cylinder attached to a cylinderrotor; Fig. 14 shows a partially sectional, partial elevational view of an axial piston compressor or air-pressure motor; and Fig. 15 shows a partially broken, partially sectional, plan view of a radial piston machine according to the invention.

31 Similar reference characters denote corresponding features consistently throughout the attached drawings. These drawings are made for clarification, not for any restrictions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Fig. 1 shows a sectional view of an oil-free axial-pistonmachine as a high pressure pump, in particular, for non-lubricating fluids like water. Six cylinders 2 are disposed in a rigid single-piece cylinder rotor 5 and slide upon a slanted control plane 10, being the front side of the stationary control plate 9. Said control plate 9 is obliquely mounted,on the endplate 7 at an inclination angle of about 50. Over one half of the control plate 9 being high pressure and on the another half being low pressure where being located the low pressure channel 24. The control plate is divided in a stationary high pressure half disc or side 55 and in a stationary low pressure half 56 (Figure la). The cylinder 2 being circularly moved, with their ports or openings sealingly sliding upon the control plate 9, and experience said two pressure levels within one revolution. Thereby, the pistons 1, actually the piston rods 15, are pulling in time over the low pressure half 56 against the delivery or high pressure in the housing 46. Consequently, the piston seal 28 must be pressure-tight in only one direction and only in time over the low pressure half 56. The piston-sealing element 28 shown here is a cone shaped special plastic wiper 28 with a relative stable or firm body diameter but with a flexible sealing lip. The body diameter of the sealing elements are smaller than the diameter of the cylinders to provide shifting space for the disparities.

32 The cylindrical housing or casing 46 consists Qf the endplate 7, and a flange 6, both being connected by a pipe 8. The low pressure or inlet port 12 is located in the endplate 7, nearby the control mechanism, and the high pressure or outlet port 13 is located in the pipe 8, preferably on the top, to exhaust the air from the pump.

The cylinder rotor 5 is interengaged and guided by the pistons 1 from a piston rotor 4 and rotates with the same average speed as the piston rotor 4. The cylinder rotor 5 has no self-guiding parts, such as like a shaft.

Each piston 1 operates in one respective cylinder 2. Thd pistons 1 are securely attached to the piston carrier 11 via strong piston rods 15 having threads 47 on the end. The piston carrier 11 is securely mounted on the shaft 3 via a tapered portion 48 and a thread 49. The piston rotor 4 consists of the piston carrier 11, the piston rods 15, and the pistons 1, which are fluidly connected, that is, without bearings or bearing-free, or integrated to form one piece, including the shaft 3. The piston carrier 11 has on its backside a husk or sleeve 16 with drive dogs 64 an end thereof to drive a rotating sealing part 17 of the mechanical shaft seal 50.

The piston rods 15 are being swept-back attached or slantways in tangential or circumference direction to the piston carrier 11 in order to bring the tractive or pulling force vector along a longitudinal axis defined by each of the piston rods 15. (Balance in peripheral direction).

The axial balance of the entire machine can be described briefly as follows. In the middle within the machine three pistons 1 separate the high pressure within the machine from the low pres- 33 sure on the outside, ergo they unbalance both rotors. The piston rotor 4 is counterbalanced by the shaft seal with the same size of three cylinders 2. The cylinder rotor 5 is counterbalanced by a low pressure field around a low pressure channel 24 with the same size of three pistons 1 or cylinders 2.

The same situation detailed: The sum of all of the average axial forces on the piston rotor 4 is zero. At any time, there are three of six pistons 1 just over the low pressure half 56 of the control plate 9. These three working pistons 1 generate a pulling force due to the pressure difference between the high pressure in a housing 46 or pipe 8 and the low pressure in ihe three cylinders 2 which are just being over the low pressure half 56, and being connected to the low pressure channel 24, and the input 12. The tree working pistons of the six pistons 1 have together the same area content as -the cross section of the sealed diameter of the drive shaft, which is actually the cross section of the husk 16. In respect to the hydrostatic pressure balance of the piston rotor 4, the outgoing shaft 3 pulls like an additional seventh larger piston (husk 16) but in an opposite direction. Now, if the pressurized areas with an opposite force vector, that is, three pistons 1 and the cross section of the husk 16 for the shaft seal 50, have the same area content, then, the entire rotating power part is axial in balance; this includes the piston rotor 4 with the pistons 1 and the drive shaft 3. (Radial remains a force which bent the shaft lateral). The useful torque- generating tangential forces on the piston carrier - ton rods 15. Consequently, the 11 remain, generated by the p fluid power is directly converted into a useful torque, and vise versa. The piston force is not transmitted through bearings. In 34 other words, even when the pistons 1 have to work against high pressure, they generate nowhere burdensome bearing or contact pressure.

Practice has shown that such a pump at 100 bar or more can be directiy attached to an electrical norm motor having standard ball bearings. The axial force balance is in practice not exactly zero. A specific axial preload is advantageously in order to get the axial-clearance out of the ball bearing to suppress any axial vibrations.

This high pressure water pump can operate vise versa as a water hydraulic motor. This unique concept is simple, powe:ful, and highly efficient. This mechanism does not depend on the inclination angle between both rotors, like conventlonal axial piston machines.

Balance of the cylinder rotor:

At high pressure in the housing 8 or 46, it is advantageously to apply also an axial pressure balance for the cylinder rotor 5 to release it from any burdensome contact pressure against the stationary control plate 9.

The cylinder rotor 5 can be considered first of all as a full disk having two oppositely circularly end faces with effective pressure fields, generated by two pressure levels, the high pressure in the housing 46 and the low pressure in the low pressure channel 24 and input 12.

The circularly face of the cylinder rotor adjacent the control plate is the control face 45 which is profiled. A ring-shaped area between the circular border lines 19 and 20 is lapped and the only sealed area for the channel control mechanism. All other areas of the control face 45 are hollow and they don't touch the control surface 10, except a ring on the outer skirt of the control face 45 which operates as a weat ring which don't sealed up.

One half of the cylinder rotor, the half, just being over the stationaryhigh pressure half 55 of the control plate 9, is a priori in balance because there is everywhere the same pressurel the high pressure of the housing 46, presupposed there are pulling pistons I only. But in three cylinders, just being over the low pressure half 56, is low pressure. This fact defines a low pressure area for the cylinder rotor because this portion of the pressure field hangs on three pistons 1, ergo on three piston rods 1 and finely on the piston carrier 11. On the other hand exists a counterpart, that is a low pressure field around the control channel 24. The size of this low pressure field can be adjusted and equalized to its counterpart (three cylinders) to achieve a proper pressure balance of the cylinder rotor.

71 Remember, the cylinder rotor 5 is axial in balance if the overall size of the pressure areas on both circularly faces are even. Therefore, the low pressure area between the cylinder rotor 5 and the control plate 9, an area around the kidney shaped control channel 24 which is a larger kidney shaped area, must be adjust to the same size as three cylinders 2.

If this sealed area would be less than three cross sections of the cylinders 2, the rotor would lift-off; if this area would be larger than three cylinders, the cylinder rotor would be pressed against the control plate.

For an even area content, the ring of the sealed area or the radial distance between the circular border lines 19 and 20 must be narrower than the diameter of the cylinders. Therefore, the 36 cylinders must be partly closed (otherwise they would not be sealed up). in practice, this sealed low pressure area around the channel 24 is just a little larger than the sum of tree cylinder cross sections to gain a necessary sealing pressure. This area is about the half ring area between the circularly lines 19 and 20 which border the sealing area in radial direction.

If the whole cylinder cross section would be open and the border lines 19 and 20 would have to go around them, the area would be larger than three cylinder cross sections because there is an unwanted and unbalanced area 21 between the cylinderz and between the border lines 19 and 20 as shown in figure la. The area 21 must be sealed for a proper control mechanism in the low pressure half 56 and there is low pressure underneath the cylinder rotor but high pressure on top of the cylinder rotor, therefore unbalanced. This area must be counterbalanced by another unbalanced area with a contrary directed force vector.

This is the reason for a partly closing of the cylinders, to counterbalance the unwanted area 21 with the new gained area 22 under the cylinders with about the same area content but with high pressure in the so called low pressure half 56.

The resulting force from the area 22, that is a high pressure cushion, is directed away from the control plate and the force from the area 21 points at the control plate and the desired balance is achieved.

All other forces are a priori balanced because everywhere is high pressure.

In respect to an axial balance, the cylinder rotor 5 can be treated like an outgoing shaft wherein a shaft seal has a cross 37 section of three cylinders 2. Actually, the cylinder rotor 5 works here as a sealing element for three pistons 1 which separate the high pressure from the low pressure channel 24.

These are different ways to describe the same situation, the pressure balance of the cylinder rotor'5. Figure la illustrates this situation. It sbows this area 21 in a view of the cylinder rotor 5 on the control plane 10. The area 21 is defined by the circumference of two neighboring cylinders 2 and both of the circular border lines 19 and 20, the interior line 19 and the exterior line 20. The circular lines 19 and 20 borders the entire ring shaped sealing area and define actually steps on the control face 45 of the cylinder rotor 2. The size of the area 21 is almost equal to or a little larger than the size of the new area 22, that is, the covered part of the bottom of the cylinder 2.

Further, Fig. la shows the contour of the control plate 9 or control plane 10 with a reniform or kidney shaped control channel 24 on the low pressure or working side 56 and the control groove 25 on the high pressure side 55. In practice, the line 20 will be shifted just far enough to the inside that the cylinder just not lift-off from the control plate 9.

The balance of the cylinder rotor 5 is optimal if the disc loading of the system will be'just equal to the necessary contactpressure to achieve a proper pressure tightness.

An optimal pressure balance is important- specially for a start of a small water hydraulic motor because the static or stationary friction is greater than the dynamic friction.

In absence of any fluid pressure, the sealing pressure for the cylinder rotor 5 is provided via a compression spring 32, for 38 instance, at an initial start of the machine. It is located in the center-line of the piston rotor 4 and is pressed between the end of the shaft 3 and a step on the spacer pin 14 in order to push the pin in the cylinder rotor 5 and the rotor against the control plate 9. The spacer pin or pole 14 is swingable gimballed or slantways pivotally borned in a spherical hole 23 which defines the pivot point of the cylinder rotor 5 in a co-rotating system. This point lies in the intersection of both axes and axially in the middle of the stroke motion. The spacer pin 14 has a certain length to prevent a lift-off of the cylinder rotor 5 from the control plane 10. If the machine works under-pressure this device is not necessary.

Figure 2 illustrates a hydrostatic pressure balance of the cylinder rotor on both halves, the low and the high pressure half, separately.

Fig. 2 shows the control plate 9a with the control plane 10a, a channel or canal 18a, and a half cylinder rotor 5a having four large cylinders 2a. The pistons are pulling over the low pressure half 56 and pushing over the high pressure half 55, and about half of the delivery pressure is in the housing. Here, the sealingly sliding side of the cylinder rotor 2a, its control face, is total plain or non-profiled and the control plate 9a is profiled by a lower level an the low pressure half, area 26. Practice has shown that it is advantageously to profile only the control plate 9a instead of the cylinder rotor. The control channel 24a on the low pressure half 56 is smaller than the control channel 25a an the high pressure half 55 in order to balance both sides separately. On the low-pressure-half 56, as 1 c is shown balancing area 27 39 on the right, is the same as in the aforementioned procedure. On the high pressure half 55, the covered is much smaller, because in this time, the delivery pressure is in the cylinder 2a and the pressure in the housing 46 ^only about half of the delivery pressure. A balance can be achieved on both halves 55, 56, in any case, by varying the different areas, actually by profiling the control plate 9a in a proper manner.

Fig. 3 shows a pulling piston la in the cylinder 2 on a piston rod 15a, and a slanted sealing element or wiper 28a. This wiper 28a is not rotational symmetrical and is not rotatable borned. This is in order to eliminate the inclination of the slight elliptical sealing-line in the cylinder 2, and therefore, the asymmetrical, that is, not rotationally symmetrical, fluid pressure around the axis of symmetry of the cylinder wall, in time over the working side or or low pressre half 56. Then the cylinder rotor is almost torque-free. This asymmetrical wiper 28a can be used instead of the slanted piston rods. This seal is pressure tight in one direction only.

Fig. 4 shows the piston la with a piston ring 28b being spherical on its outside to form an exact circularly sealing line which is always strait in the cylinder but various slanted on the piston ring 28b. Consequently, the sealing plan is never slanted in the cylinder 2; and furthermore, the fluid-pressure generates no lateral forces and no torque on the cylinder rotor 5. Like a classical piston ring, this piston ring 28b is fixed along the stroke or longitudinal direction, has an interior radial clearance and is rotationally free. Between piston ring 28b and the piston lb or better piston rod 15b is a suitable radial or lateral clearance in order to allow the same to shift laterally in any direction for an predetermined amount while the spherical outside of the sealing element remains permanently on the cylinder wall 58. The piston sealing element 28b is selfaligned to the cylinder wall. The center of the piston lb and the piston rod 15b, that is actually a screw head, being allows to go out of the center of the cylinder for a certain predetermined amount. Said clearance is an important parameter of such a machine. This certain movability, possibly together with other shiftable parts, enables said lateral shifts to compensate or to work up (not eliminate) said displacements between piston lb and cylinder 2 caused by the inclination between both rotors 4,5 and enables this invention to work.

When the piston ring 28b is of synthetic material, like plastic, the sealing pressure and memory of elasticity can be supported by a steel ring spring 30. This sealing element 28b is pressure tight in both directions and suitable for the majority of all applications. Actually it is a combination between a seal and a wear ring because the piston himself never touches the cylinder wall.

Now referring to Fig. 5, another version of a piston lc, in which no torque is generated on the cylinder rotor 5 by fluid pressure which minimizes lateral forces for the pistons lb.

There is a clear locally separation between the guiding function and the sealing function on an extended piston sealing element 28c.

1 41 A spherical piston lc is swingable or gimballed borned in a guiding and sealing element 28c which is on the inside spherical and on the outside cylindrical. It works, if.it is in thin plastic material, in the zone around the equator from the spherical piston 1c, like a wear ring, and on the upper zone, like a wiper with a sealing lip 29. A sealing lip can be on both sides (not shown). The shown piston version is pressure tight only in one direction. The preload provided again a circularly spring 31.

When using large pistons, such as for engines, piston rings and oil piston rings are placed in the cylindrical part 28c.

Now referring to Fig. 6 a sealing element 28d is located on top of a conical cylinder 2d, where the cylinder 2d has its smallest diameter, and the piston is a smooth plunger piston ld. This sealing element works like a wiper on the plunger, it is fixed in a longitudinal direction on top of the cylinder 2d, but it is laterally shiftable and flexible. The wall of the cylinder 2d is conical and wear free. But in this case a dead volume remains in the cylinder 2d.

When the entire cylinder rotor (not shown) is made from elastic material, the upper narrowest end of the cylinder 2d can take over the function of a sealing part 28d suitable for a very simple pump version.

Fig. 7 shows, on the one hand, the machine with the plunger pistons le and the sealing elements 28e according to the example from Fig. 6. On the other hand, it is similar to the structure shown in Fig. 1, with basically the same working mechanism. This is an example to show that combinations between variations are 42 possible too. The main difference here is that a sealing element or wiper 28e sweeps on the plunger piston le or respective piston-rod 15i instead of sweeping on the wall of the cylinder 2b. A flexible sealing element 28e is placed on top of the cylinder 2b in the cylinder rotor Sa, and it is slightly sideways or laterally shiftable. Further, the spring 32a is stronger and is rotationally coupled on both ends, and is preloaded in a rotating direction in order to remove lateral forces from the sealing elements 28a. A more stable spacer pin or distance bolt 14a, borned in a spherical hole 23a, centers the cylinder rotor 5b.

Fig. 8 is another version of plunger piston If, but the piston plunger is in soft material and the cylinder 2c is in rigid material. The upper narrowest edge of the cylinder 2c is rounded and presses a little against the soft plunger If for proper sealing. This version is suitable for use as a simple pump and for low pressure only. A metallic piston rod 15d is thin and flexible. There is practical no tractive or pulling force caused by fluid pressure an the piston rod 15d, if it is sealingly attached on the piston carrier 11.

Figure 9 shows a very powerful and wear resistant piston actuating mechanism or power train, that are both rotors 4e,5e for use in mainly all axial piston machines, as one is shown in Fig. 1 at high performance and without lubrication.' The strong piston rods 15e are attached to a piston carrier lle or rotor 4a via a long thread that is not tightened by a nut or the like. The piston rods 15e with the pistons lk, which are actually screws, 43 are secured against loosing by a ring compression spring 33 on the backside thereof which lies in a fitting cut-out of the six screws to prevent a turnout of the screws. This can also be done by a ring (not shown) fitting in an cut-out or bore 44 of the six screws (shown only two) define respective piston rods 15e, or it can be accomplished by using other locking divises. Practice has shown that a normal clearance in a thread alone allows such lateral shifts which are already enough to compensate the said deflections for small inclination angles between both rptors. A greater lateral.mobility or amplitude for the pistons lk can be achieved very easily, that is by simple lengthdning the crews or piston rods.

The spacer pin 14e with the spring 32e performs the same task as in Fig. 1.

The sealing element 28k is partly sphericalland also slightly laterally shiftable (both lateral mobilities can work together or alone) with respect to the piston rod 15e or piston lk, and is self-alignable with respect to the cylinder 2e like a floating arrangement. The piston seal element 28k is longitudinal secured via a compression spring 34 and the pistons work only over said low pressure half or side by pulling against a delivery pressure in the housing 46.

The spring 34 also prevents major damage from being caused by foreign particles which may stuck between a mostly softer piston seal and the cylinder by allowing a jamming between piston seal and cylinder. In this time, if the friction in the cylinder is higher than the spring load, the piston seal moves reciprocally along the piston rod instead along the cylinder. In other words, this machine can still run while one piston don't work anymore 44 and its piston seal jams and don't moves anymore in the cylinder in order to prevent a destruction of the cylinder wall. Practical the piston seal experienced an immidiate stop, if the friction exceeds a certain amount. It would be never possible to stop the entire machine in such a short time as a spring reacts without a destruction of the machine. With such simple springy devise, one gains enough time to stop the machine without major damage by a foreign particle; or, for instance, such a gasoline pump or hydraulic motor can work with the remaining cylinders until an airplane is landed. The spring 34 can also be used in a position of its shortest length without this extrhordinary function. Additionally, the spring 34 can provide a radial preload for the plastic sealing element 28e. This is shown in Fig. 9a which is an enlargement of a piston lk from figure 9.

If the material of the piston seal 28k is soft, its both axial ring faces can be covered in metal, thenthe piston seal 28k is a plastic metal compound structure (not shown), Figs. 10a and 10b show another pulling piston If attached to a piston carrier 11f by a simple attachment. The piston If and a piston-rod 15f with a ball-shaped end 35 are one piece. All piston connecting members can be attached to the piston carrier llf through a slot 36, and bear in a spherical hole 37. The spring 34a straightens and secures the piston If, holds the sealing element 28f in position, provides it's radial preload, prevents damage during jamming in the cylinder 2, and enables a shortening of the stroke motion.

Fig. 11 shows another piston lg with athin metallic piston-rod 1 15g but with a large solid mantle 38 in rubber, sealingly attached to the piston ig and to the piston carrier 11g, to release the piston-rod 15g from the tractive force when the piston lg is pulling. The piston seal 28g is spherical and radially preloaded by a flat, cylindrical ring spring 59.

Fig. 12 shows a pushing piston 1h. A piston seal 28h is shown here oppositely directed and axially secured on an end of a piston rod 15h, but with a radial clearance. It is shown here as a compound of metal with an exterior spherical part in softer sliding material. In this case, the housing of a pump with pushing pistons such as these must not be pressurized.

Fig. 13 shows a slightly laterally shiftable cylinder 2i on the cylinder rotor lli, which is here actually only a disk 60 with the control channels 18i. I On top is the frame 39 with holes for the cylinders 2i. An O-Ring 40 seals up the bottom of the cylinder 2i against the pressure in the housing and controls the lateral shifts of the cylinder 2i.

A flexible cylinder, like a rubber tube, and a piston, like a hard ball, would also be possible instead of shiftable cylinders or flexible piston rods.

Fig. 14 shows a 6-cylinder axial piston machine, in particular, for a compressor with two shafts. A piston rotor 4j is guided via a shaft 3a in an end plate 6j. A cylinder rotor 5j is guided via a shaft 3b in an end pl ate 7j. Both shafts,3a,3b are slanted with respect to each other with an inclination angle and a paint of intersection 41 in the middle plane 42 of the stroke motion, 46 which is simultaneously the middle plane of all six spherical piston seals 28j. The piston rods 15j are stiff. A necessary shift will be executed between the piston seals 28j and the pistons lj via a radial clearance 43. The pistons lj are spherical ana the bottoms of the cylinders 2j are spherical as well to avoid a dead volume. The channel control mechanism is located on the bottoms of the cylinders 2j, closely to the shaft 3b. The control plate or ring 9j has a cone shaped control surface 10j and is elastically and sealingly fixed to the end plate 7j. Control periods are predicted by sliding the cylinders 18j with the openings 18j upon the reniform or kidney shaped statiodary control channels 24j in the control ring 9j which are connected to the inlet/outlet ports 12j and 13j. The ports 12j and 13j that functions as an inlet or outlet port depends whether the machine operates as a compressor or an air motor. Every desired inner compression is possible without using valves. A compressor of this type can work with water as well as oil as an operating or auxiliary fluid in the housing 46 for sealing and cooling; or may operate, as shown here, totally dry, that is, without any fluid. When required, the machine can also run with high speed. The housing 46 can be pressurized lower than the delivery pressure to minimize the thrust on both rotors 4j,5j.

A "Displacement Turbine" may run one unit as compressor to feed a combustion chamber followed by a second modified unit as a turbine. This units can be cooled with oil spraying to the outside of the rotors. The control ring 9j with the cone shaped control surface 10j can easily be made in ceramic.

Fig. 15 shows a 4-cylinder radial piston machine according to 1 47 the invention. Pistons lk and cylinders 2k are radial directed. Both rotor axes 61; 62 are shown parallel to one another and are spaced only a small distance apart, or one is slightly eccentric. Therefore, the length of the stroke motion is very short compared with the diameter of the rotors 4k,Sk, and the amplitude or elongation of lateral shifts of the iston seal 28k is much wider compared with the prementioned axial piston versions. But the piston seal 28k is not necessarily spherical. The piston seal 28k is held again in a longitudinal position on the piston 1k via the compression spring 34k and via radial force. In this case, the housing 8k is pressurized, ergo the pistons 1k and the piston rods 15k are pulling. The stationary control surface l0k shown here is cylindrical. The control channels 24k shown here are in the cylindrical housing 8k and are connected to the inlet/outlet port 12k and l3k.

It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.

48

Claims

1. A rotary piston machine with directly guided parts in the piston actuating mechanism, ergo without power transmitting bearings in the power train, comprising: a housing having at lcast one inlet and one outlet and disposed therein at least: two rotors rotatable on two different axis, at least one piston rotor with a piston carrier and a formation of pistons, at least a cylinder rotor with the corresponding formation of cooperating cylinders, wherein both rotors are interengaged and rotational coupled by the pistons in the cylinders, said cylinder rotor being of an unitary compact uninterupted construction and slides sealingly with its openings upon a staying control surface having control channels and control grooves; said pistons are directly and bearing-free attached on said piston carrier via strong piston connecting members; said axis of both said rotors are closely neighboring, and/or forming or obtaining a small angle and a small distance respectively and generating a relative short stroke motion only, to eliminate most of all disparities between the pistons and the cylinders by utilization the concerning characteristic of the cosine function around 00; said actuating mechanism contains, lateral to the stroke motion and for a predetermined elongation or amplitude, shiftable elements, that are piston sealing elements and/or piston rods and/or cylinders respectively.

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2. A rotary piston machine according to claim 1, wherein all 1 If 49 said piston rotors within one machine, being rigidly connected to each other, and each said piston rotor having at least one formtion of pistons, and having attached opposite directed forces by pulling or pushing pistons or piston rods and shafts respectively, are pressure balanced, wherein both sums of all pressurized areas or pressure fields, having oppositely directed force vectors, are substantially equalized.

3. A rotary piston machine according to claim 1, wherein each open end of said cylinder, adjacent said control surface, is partly closed, to reduce the size of a low pressure field around a low pressure channel in the control surface, and to create a high pressure cushion instead, to generate a proper force pointing away from the control surface, and to balance the cylinder rotor upon the control surface.

4. A rotary piston machine according to claim 1, wherein the piston rods are axial directed and are pulling'only in time over the stationary low pressure half of the control plate, the compact disc shaped cylinderrotor having an end plane or control face containing the openings of the cylinders which sealingly slide upon a control plane, wherein the size of the openings of each cylinder is about the half of the cross section of a cylinder, and the size of the entire sealed area around the low pressure channel between said control plane and the control face of the cylinder rotor is substantially equal to the sum of the cross sections of the cylinders which are just sealingly connected to a low pressure channel.

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5. A rotary piston machine according to claim 1, wherein the piston rods are axial directed and the pistons are pressuretight and working in both directions, whereby the pistons and piston rods are pulling in half the time of one revolution and locally over the stationary low pressure half of a control plate, and pushing over the high pressure half respectively, and the cylinder rotor being pressure balanced over both halves separately by profiling the control plate to create different pressure cushions respectively.

6. A rotary piston machine according to claim l,' wherein said piston rods are pulling only, and said rotary piston machine includes: a piston rod attached on a piston carrier, a piston seal, and.a compression spring, wherein said compression spring is placed around the piston rod to hold the piston seal in its position at a predetermined amount of force.

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7. The rotary piston machine according to claim 1, wherein piston rods are axial directed, and said cylinders, prefe- two, are bent around an imaginary global surface, forming a part of a torus, and having arched cylinder axes forming a part of a great circle of said imaginary global surface and its center lies in the point of intersection of both rotor axis.

8. A rotary piston machine according to claim 1, wherein each said piston rod and each said plunger piston respectively are swept-back or inclined attached to the piston carrier so as to be tangentially or in circumferential direction slanted with a small angle.

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9. A rotary piston machine according to claim 1, wherein said piston sealing element being positioned asymmetrically slantwise relative to said piston rod with a specific inclination angle in a circumferential direction to generate torque on said cylinder rotor in the direction of rotation.

10. A rotary piston machine according to claim 1, wherein said pistons are cylindrical plunger pistons, and said cylinders being conical and said sealing elements being disposed at the narrowest end of the cylinders, said sealing elements further wipe along said cylindrical plunger pistons, and each said sealing element being self-aligning with respect to each said plunger piston.

11. The rotary piston machine according to claim 1, wherein said rotary piston machine is an axial rotary piston machine including a cylinder rotor, a piston rotor, a control surface, a compression spring, and means for loosely fastening said cylinder rotor against said control plane, said fastening means including an axial spacer pin in the center line of the piston rotor between both of said rotors and a compression spring around the spacer pin in order to push the cylinder rotor against the control surface at a predetermined force.

12. The rotary piston machine according to claim 11, wherein said spring is a combined compression and torsion spring, rotational coupled on both rotors, and preloaded in turning direction.

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13. The rotary piston machine according to claim 11, wherein said spacer pin has elasticity of torsion, said spacer pin connecting both of said rotors in torsion suspensions and being preloaded in the direction of turning.

14. The rotary piston machine according to claim 1, wherein the piston rods are only pulling, and each said relative thin and slender piston rod is sealingly shrouded with a substantially pliable material at a diameter which is almost the diameter of the piston to relieve said piston rods from a tractive force caused by a fluid pressure in said housing.

15. The rotary piston machine according to claim 1, comprising a cylinder rotor being of unitary, compact construction, wherein the cylinder rotor is guided by a shaft or stub shaft..

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16. The rotary piston machine according to claim 1, wherein said bottoms of large cylinders having two locally separated openings, rotating sealingly upon two separate circles from the control surface with separate control canals.

17. The rotary piston machine according to claim 1, wherein said cylinders having a large diameter and an inside, and said piston rods are axial directed in this rotary piston machine including:

a rotational symmetrical control part on said control surface close to an axis, said bottoms of the cylinders are open an the inside only and sealingly sliding on said stationary rotational X 53 symmetrical control part.

18. A rotary piston machine according to claim 1, wherein each said cylinder is integrated in said cylinder rotor such that each said cylinder is laterally shiftable for small predetermined amplitudes.

19. A rotary piston machine according to claim 1, further including: means for flexibly attaching said cylinders to said cylinder rotor.

20. A rotary piston machine substantially as herein described with reference to the accompanying drawings.

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