This invention relates to a rotary working machine provided with an assembly of working chambers with periodically variable volume, in particular a compressor.

Since 1908 is known a blade-type working machine, employed particularly as a compressor, consisting of a rotor, eccentrically supported inside a stationary block and of a set of blades, slidable in grooves of the rotor. Rotation of the rotor causes the blades moving in and out, which are controlled by an inner surface of the cylindrical block, thus permitting formation of working chambers with periodically variable volume, enabling intake and compression of a medium.

A disadvantage of the blade-type working machines is in energy losses due to a friction of the rotating blades against walls of the cylindrical block, negatively affecting the efficiency and a durability of such machines, particularly at higher speeds.

Since 1927 is known a Pneumaphore type blade compressor, working on a principle of oil injection into a compressed air, permitting a partial reduction of energy losses and a blade wear. Similar purposes had a construction of compressors featuring blades made of light aluminium and, since 1964, even lighter plastics. Blade compressors of such design exclude, however, application of high speeds, limitation being in considerably lower strength of the blades.

United States Patent US 5,379,736 discloses a combustion engine consisting of an air compressor, a similarly designed exhaust gas decompressor and a combustion chamber positioned between the compressor and the decompressor. The compressor is provided with two rotating cylinders: an outer cylinder and an inner cylinder, respectively, interconnected and fixed on a common driveshaft, eccentric both in relation to the driveshaft's axis and between themselves. Between the rotating cylinders is situated a stationary intermediate unit provided with blades, swivelling on pivots fitted around an axis of the unit, wherein the blades during rotation of the eccentric cylinders take positions forming, between neighbouring blades and surfaces of the cylinders, chambers with periodically variable volume. A movement of the blades is forced by planetary gears, connecting the driveshaft with the pivots, being axes for the blades' rotation. Furthermore, the intermediate unit is provided with inlet and outlet flanges with valves, controlled by cams fixed on the driveshaft. The blades are rotating in the same direction as the driveshaft, but at half of the driveshafts' angular speed. Such design reduces considerably the expenditure of energy to overcome friction, but a certain energy is consumed to overcome inertia moments of the numerous moving parts of the machine.

German Patent DE 1 551 101 describes a rotary combustion engine, featuring oscillating working elements, set on pivots in a rotating ring and controlled by specially shaped two- or four-lobe cams, located on both sides of the ring. Working elements have, in a section, a shape of triangles with convex sides, the tops of which slide on surfaces of both cams, forming working chambers with periodically variable volume, causing intake and compression of a medium. During a rotation of the driveshaft, each oscillating working element is pressed by a centrifugal force against an inner surface of one cam, and at the same time tightened in relation to the central cam's outer surface by means of sealing strips, pressed against it.

A disadvantage of such engine, prevailing in other rotary engines, is in considerable energy losses, due to friction of numerous working elements against surfaces of cams, and in a difficulty of sealing the extremities of working elements in relation to the cams' working surfaces.

Polish Patent PL 109 449 and its German equivalent DE 1526408 disclose a rotary combustion engine, featuring an elliptic cylinder, inside which is moving a system of five pistons, connected by joints to create a closed chain, while between inner concave surfaces of the pistons and the elliptic surface of the cylinder, working chambers with periodically variable volume are formed. Pistons, being approximately triangular in section, are interconnected by sealed setting pins, placed in recesses in neighbouring pistons and provided with sealing strips, pressed against the elliptic surface of the engine's cylinder. A movement of the pistons is controlled by two rotors or discs, formed by joint-connected five segments with axes constituting extensions of axes of setting pins, located on both sides of the engine and transmitting torque to the engine's driveshaft.

A disadvantage of such construction, and other similar designs of working machines, in which kinematically connected working elements form a closed chain, is in a presence of variable moments of inertia, increasing friction losses, and thus reducing efficiency of the machines.

International Patent Application WO00/42290 describes a rotary combustion engine, consisting of an engine block and of a rotor, located inside it and featuring four movable pistons, in the form of double-arm levers, oscillating around axes parallel to a central axis of the block and at the same time revolving together with the rotor. The pistons are provided with thrust rolls, which during movement along a circumference of the engine block, are driven by a system of cams, consisting of an outer cam and an inner cam. Mating of the thrust elements of the pistons with cam surfaces forces, during the common rotation, oscillating of the pistons around semicircular projections on the rotor. The pistons are sealed against each other by means of toothed contact surfaces, while between their working surfaces and an inner cylindrical surface of the engine block are formed chambers with periodically variable volume, enabling intake and compression of a medium. A disadvantage of such design is in considerable friction forces, generated between the concave surface of pistons and the semicircular projections on the rotor, in connection with important mutual pressures between mating surfaces. Considerable frictional losses arise also on the thrust elements of pistons, driven in a slot between the two cams.

German patent DE 622 554 relates to a working machine with oscillating pistons, swivel fitted in sockets of a rotor's body The pistons constitutes, along with a surface of the rotator's body, working chambers with periodically variable volume, which are sickle-shaped. The oscillating pistons are provided with counterweights, swivel on their pivots in the rotating rotor's body, and slide with their sealing edge, which close the working chamber, on a eccentric in relation to the rotor's axis circumference of a stator having circular cross section. Oscillating pistons are provided with counterweights, which position and size are selected in a way enabling the inertia moment of the piston (caused by a centrifugal force) to be substantially equal to a torque caused by an acceleration or deceleration of the oscillating piston.

Balancing of torque, resulting from an acceleration and deceleration of the piston's oscillation, can be done by appropriate adjustment of the oscillatory piston's counterweight only for one, determined rotational speed.

German patent DE 898 697 discloses a working machine according to the preamble of claim 1 and provided with oscillating pistons disposed in sockets on an outer circumference of a cylindrical rotator. The pistons are provided with rolls, which move on an inner cam surface of a stator surrounding the rotator and control an oscillating motion of the pistons. A surface of the rotator along with a surface of the stator form working chambers with periodically variable volume. The oscillating motion of the pistons is limited by stop members, which are mounted on an outer surface of the pistons and guided in grooves, in order to avoid a contact between large surface areas of the pistons and the stator. In another embodiment, oscillating pistons are disposed in cylindrical sockets on an inner outline of an annular rotator surrounding a stator. A cylindrical outer surface of the stator is eccentric in relation to a rotator's axis and forms a guiding surface for sealing edges of the pistons. In both embodiments, the oscillating motion is forced by a centrifugal force resulting from a displacement of a mass centre of the pistons in relation to their oscillating axis, or from a rolls action, or from a special load.

Disadvantages of that working machine arise from a large motion resistance of the rolls, a motion resistance of the pistons in the sockets and a friction between edges of the pistons and the surface of the stator.

It is an object of the invention to provide a rotary working machine, according to the preamble of claim 1 and equipped with a group of working chambers of changeable volume and placed in the block, in which the rotor rotates with pendulum pistons - working elements, seated in cylindrical sockets and sliding during rotation in the internal part of the block constituting a special curve, which ensures significantly less losses caused by friction, and thus correspondingly increase is the efficiency of the action of the machine.

Research work, which led to the invention, has proven that it is possible to considerably limit the energetic losses, which result, in known rotary machines with oscillating pistons, of forces acting on individual components of these, by such a correlation of kinematic connection system of the oscillating pistons with distribution of their masses, as to reduce, for any rotation speed of the machine, movements of these oscillating pistons to resonance oscillations in the field of centrifugal force. The resonance character of the oscillating pistons' oscillations enables maintaining the motion by solely overcoming a minor resistance of their replacement in relation to the rotor. The invention provides a rotary working machine according to the preamble of claim 1 and assembled with a block of which the central part is provided with a stator in the form of a camshaft, the internal surface of which constitutes the surface guiding the pendulum motion of the blade type oscillating pistons in cylindrical sockets of the cylindrical rotor placed inside this stator in camshaft form and propelled with the aid of a separate engine, in which the contact edges of these blade type oscillating pistons are guided by the internal surface of the camshaft form of creating , between this surface, and the intake apertures of the controlling cam and possibly the surface of the cradle type oscillating piston, working chambers of changeable volume connected during the rotor rotation to the corresponding insight pipe of the camshaft and annular slot evacuating compressed medium, in which the outline of the cross-section of the camshaft form stator vertical plane to the axis of the rotor constitutes an equally distant line to the curve, which is described by two parametric equations:

Χ(φ)-ί sincp + r sin(q>+v+6((p))

Υ(φ)=1 coscp + r εΐη(φ+γ+θ(φ)) where:

φ is a rotation angle of the rotator from a position of minimum potential energy, that is from a position, in which points O, Oi, S are on a single straight line determining an axis OY in Fig. 5;

Χ(φ) denotes an abscissa of a position of a vertex point of each of the oscillating pistons of the working element in a co-ordinate system having a centre in the point O being the cylindrical rotator's axis of rotation, after its rotation through the angle φ;

Υ(φ) denotes an ordinate of a position of a vertex point of each of the oscillating pistons of the working element in a co-ordinate system having a centre in the point O being the cylindrical rotator's axis of rotation, after its rotation through the angle φ; i is a distance OO^ of the working element oscillation axis from the cylindrical rotator's axis of rotation;

r is a distance of the vertex point from the oscillation axis of the working element;

Y is a constant angle formed between the axes O^S and O^C, where S is a mass centre of the working element; and

θ(φ) is an angle by which the axis O^S deflects during the rotator's movement through the angle φ,

wherein a relation between the rotation angle φ of the cylindrical rotator and the deflexion angle □ of the axis O^S of the working element is expressed by an equation: θ(φ) = 2 arcsin sin - sin ψ(φ)

where a relation between the angles φ and □ is described by tabulated values of elliptic integrals.

Rotary working machine, in particular a compressor according to the invention, is characterized by a compactness of its design, expressed in that a ratio of total change of the working chambers' volume (equivalent of a displacement volume) to a volume of inner outline of the machine's moving part is close to one. Furthermore, an implementation of the compressor has proven, that thanks to elimination of losses to overcome friction forces and motion resistance, prevailing in known similar machines, it achieves the efficiency in an order of 90 %. It is important for the ratio of the working element resonance oscillation frequency to the frequency of the rotator's revolutions to remain, in the conditions of steady movement, constant for all speeds of the rotator. This means that the machine is characterized by a high efficiency, independent on the rotator's rotational speed.

A rotary working machine according to the invention, provided with a system of working chambers with periodically variable volume, constituting a compressor, will now further be explained with reference to exemplary embodiments in the accompanying drawings, in which: Fig.1 - presents a compressor equipped with a set of 4 working chambers, each of which is equipped with pendulum a seated blade type working element - in transverse cross-section along the line A-A in Fig.2,

Fig.2 - this same compressor in axial cross-section

Fig.3 - this same compressor with dismantled parts in perspective view

Fig.4 - Radziwitt curve K _R constituting the basis of the outline of the curve controlling the compressor opening according to Fig.1

Fig.5 - cylindrical socket in rotor together with pendulum blade type oscillating piston seated in it.

The rotary compressor presented in Fig.1 , 2 and 3 is equipped with three part housing, consisting of central block 1 , and cover block 1 a and also of rear outside block 1 b, also wedged in it on the controlling cam of the cylindrical rotor 8. The block 1 is supplied with camshaft form stator 4, of which the transverse cross-section constitutes the further referred to Radziwill curve K _R . Furthermore in the block 1 is the inside pipe of the camshaft 19 through which the compressor sucks in the compressed medium and also the annular slot 21 evacuating compressed serving to conduct away compressed medium under high pressure. The block 1 is tightly closed on both sides with the aid of the flange of the cover block 1 a and the rear block 1 b connected with it with the aid of the screw 18. The cylindrical rotator 8 is wedged on the controlling cam 5, of which the pivots 13, 14 of the working unit are seated in needle type rolling bearings 15 and 16. The cylindrical rotator 8 furthermore is equipped on its internal surface 24 with four cylindrical sockets 22 symmetrically placed in its circumference with seated in them on axes 23 of the oscilatting blade type-working elements 10. Blade type working elements 10 are rotationally seated on axes. Axes 23 of working elements 10 are mounted in projections 29 protruding from rotator interior surface cylindrical sockets 22 (Fig.5).

Blade type working elements 10 have the form of a two armed lever seated rotationally in axis 23. This lever is created by two side cylindrical surfaces 30, 30' of radius equal or somewhat less than the radius of the internal surface 24 of the cylindrical socket 22. This lever is also created by front cylindrical surface 31 of radius equal to the radius of the cylindrical rotator 8 and rear surface 32 is of the outlet aperture of the controlling cam closing and giving the rotator the form of an arched wedge increasing in the direction of the side cylindrical surface 30 of the working element 10. In intersection of side cylindrical surface 30 and front cylindrical surface 31 of the working element 10 is a set of vertex points C creating the working age of this element cooperating with the surface of camshaft form stator 4, constituting in the cross-section the Radziwill curve K _R . The configuration of each of the blade type working elements 10 especially its form, dimensions and material thickness of which it is a security and the distance of the centre of its axis 23 from the rotation axis 17 of the cylindrical rotator should be so selected in order that the relationship of the frequency of the blade type working element 10 (for the specified chosen amplitude of oscillations) is the frequency of rotary movement of the cylindrical rotator 8 expressed as a natural number e.g.: 1 , 2, 3:

This condition is fulfilled, when the moment of inertia l _Qi of the blade type-working element 10 with regard to the axis of oscillation O-i fulfils the equation:

where: v is a natural number expressing a ratio of frequency of the resonance oscillation of the working element to a frequency of the rotation of the cylindrical rotator, where v = 1 , 2, 3...;

ί is a distance of the working element oscillation axis from the cylindrical rotator's rotation axis;

s is a distance of a mass centre of the working element from an oscillation axis of the working element;

m is a mass of the working element;

θ ₀ is an angle corresponding to an amplitude of the working element oscillation in relation to the rotator.

In order to ensure continual contact of set of the vertex points C of blade type working element 10 (creating the contact edge) with the surface of the camshaft form stator 4 of the block 1 transverse cross section of this opening (vertically to axis 17 of the cylindrical rotator 8) must constitute the geometric place of points forming the closed track of movement, which marks on the immobile plane of the vertex point C cross section of the blade type working element 10 moving with pendulum motion with the movement resonance frequency of the blade type working element 10 during the time of complete rotation of the cylindrical rotator 8. The geometrical place is the Radziwill curve K _R o defined in the system of two parametrical equations:

Χ(φ)=ί sinq> + r sin(q>+v+0(<p)) Υ(φ)=ί coscp + r sin(cp+Y+9(q>)) where:

φ is a rotation angle of the rotator from a position of minimum potential energy, that is from a position, in which points O, S are on a single straight line determining an axis OY in Fig. 5;

Χ(φ) denotes an abscissa of a position of a vertex point of each of the oscillating pistons of the working element in a co-ordinate system having a centre in the point O being the cylindrical rotator's axis of rotation, after its rotation through the angle <p;

Υ(φ) denotes an ordinate of a position of a vertex point of each of the oscillating pistons of the working element in a co-ordinate system having a centre in the point O being the cylindrical rotator's axis of rotation, after its rotation through the angle φ;

I is a distance 00 of the working element oscillation axis from the cylindrical rotator's axis of rotation;

r is a distance of the vertex point from the oscillation axis of the working element;

Y is a constant angle formed between the axes O-iS and O-iC, where S is a mass centre of the working element; and

θ(φ) is an angle by which the axis C^S deflects during the rotator's movement through the angle <p.

wherein a relation between the rotation angle φ of the cylindrical rotator and the deflexion angle □ of the axis 0-|S of the working element is expressed by an uation: θ(φ)

where a relation between the angles φ and□ is described by tabulated values of elliptic integrals.

The above figure of parametric equations describing the Radziwill curve K _R concerns the case of pendulum movement of the blade type- working element 10 around axis 23 of the rotation of this element 10 connected immovably with the cylindrical rotator 8.

The condition for the closure of the vertex movement track point C of the blade type working element 10, moving whether pendulum motion with regard to the cylindrical rotator 8 with resonance frequency is the fulfilment of the condition in order that the relationship of the oscillation frequency period of this blade type working element 10 (for the accepted value of oscillation amplitude) to the frequency of rotation movement of the cylindrical rotator 8 expressed as a natural number and amounts at the most beneficial to 1 or 2. In actual construction of the compressor the movement track in the immobile vertical plane to the axis of the cylindrical rotator 8 (with regard to the arising abrasion force) does not affect vertex point C, but the rounding of the age of contact of the surface 32. The rounding of surface 32 constitutes the set of contact points C with the surface of the camshaft form stator 4 (equidistant from this vertex point C). In connection with this the outline of the cross-section of the camshaft form stator should constitute the equidistant curve with drawn to the centre from curve K _R , ensuring in this manner continuous contact of points of the rounded surface 32 of the appropriate surface points of the camshaft form stator 4. In order to reduce friction of the surface referred to, the contact surface should be lubricated with an oil jet through nozzle of the intake slot of the controlling nozzle 33 on the surface of the blade type-working element 10. The oil jet shall occur beneficially during the air suction phase.

In the example construction solution presented on Fig.1 to Fig.3 the cylindrical rotator 8 is supplied on its internal surface with four sockets in which are seated blade type working elements 10. Obviously another number of sockets is also possible, which would require the corresponding construction adaptation of the placing of the inside pipe of the camshaft and the annular slot evacuating compressed medium.

The above the right action compressor presented schematically on Fig.1 is discussed below. Inside the camshaft form stator 4 opening of block 1 of the external surface 24 of the cylindrical rotator 8 and the intake apertures of the front surface 31 of the blade shaped working element 10 during its rotation for the working chamber A of variable volume. In the setting presented on Fig.1 for its clockwise rotation direction the volume of chamber A1 increases causing suction of the compressed medium through the inside pipe of the camshaft 19. After rotation of the cylindrical rotator 8 by a central angle of 90 degrees the volume of the chamber increases to the maximal value. Simultaneously in this setting of the rotator, this chamber is closed by the vertex points C of adjacent working elements 10. During further rotation of the cylindrical rotator 8 follows the reduction of the volume of chamber A3, and simultaneously oil jet through oil jet nozzle 33. Supplied working chamber to A3 the oil fulfils a triple function, because it lubricates the rear surface 32 of the blade type working element 10 creating a curved opening from the surface of camshaft form stator 4 a wedge of oil reducing friction, simultaneously sealing these surfaces and also conducting away heat being the result of the compression process to invisible coolers. In this last movement phase, corresponding to the further rotation of the rotator by a following angle of next 90 degrees follows the opening the annular slot 21 evacuating compressed medium and conducting away the compressed medium to peripheral appliances of the compressor.

Usage examination of the compressor according to the discovery showed that its optimal operation compression corresponds to a large extent of rotation frequencies of the cylindrical rotator 8. But after exceeding a defining boundary value of these frequencies further increase of rotation speed causes a proportional growth of compressor output. For example driving the compressor with an engine of 3kW power a working pressure of 11x10 ⁵ Pa and output of approx. 300 dm3 /min. was obtained.

It will therefore be understood by those skilled in the art that the present invention is not limited to the embodiment shown and that many modifications are possible without departing from the scope of the present invention as defined in the appending claims.