Abstract: A volumetric machine comprises a cylindrical screw meshing with a pinion-wheel, a low pressure port near one end of the screw, a high pressure port near the other end of the screw, and a control slide axially movable in the bore of a housing in which the screw is rotatable. In one condition, including a series of positions, the slide more or less broadens the high pressure port and thus controls the volumetric ratio of the machine, but covers any threads of the screw which are meshing with the pinion-wheel. In another condition, the slide closes the high pressure port except a stationary port but uncovers some of the threads meshing with the screw, such as to establish a part load with a predetermined volumetric ratio.

Abstract: A refrigerating machine including a compressor, a condenser, an expansion valve, an evaporator and an economizer device in the form of a centrifugal liquid gas separator, the gas space of which is connected to an intermediate pressure point of the compressor. The liquid space of the separator is connected to the evaporator via a valve controlled to maintain an annulus of liquid in the separator. The inlet of the separator is connected to the outlet of the expansion valve. The separator is driven by the compressor shaft.

Abstract: A screw is adapted to cooperate with a casing and at least one pinion-wheel for compressing or expanding a fluid within the space located between two screw threads, the casing and a tooth of the pinion-wheel. The casing and crests of the threads carry two cooperating surfaces, and at least part of one of the surfaces comprises lands defining continuity of the surface but being discontinued along any circle centered on the axis of the screw. The lands separate cells which trap formative seizure particles and, thus, reduce the clearance needed between the screw and the casing.

Abstract: A device to ensure tightness without friction and thus as reduced as possible clearance at the high pressure end of the screw. At the high pressure side of the screw, the bearing housing of the screw comprises a metal ring which is different from the metal of the screw ring and has a higher coefficient of expansion. This ring fills up a circular recess machined at the end of the screw. This device ensures an almost perfect leak-tightness in the case of compressors, or oil free expansion machines or high pressure pumps.

Abstract: A screw is adapted to cooperate with a casing and at least one pinion-wheel for compressing or expanding a fluid within the space located between two screw threads, the casing and a tooth of the pinion-wheel. The casing and the crests of the threads carry two cooperating surfaces, and at least part of one of the surfaces comprises lands defining continuity of the surface but being discontinued along any circle centered on the axis of the screw. The lands separate cells which trap formative seizure particles and, thus, reduce the clearance needed between the screw and the casing.

Abstract: A positive displacement machine such as a hydraulic pump or motor comprises a screw with several threads rotatable inside a casing and meshing with at least one pinion, and at least one low pressure port and at least one high pressure port located in the casing on either side of the pinion. The portion of the casing comprised between a low pressure port and a high pressure port is in leaktight contact with the whole length of the top of at least one thread of the screw. When said portion is in contact with the tops of two threads, no pinion tooth is in mesh between them. The threads terminate on each side of the screw on substantially equal diameters and have in their central section a swollen portion with an external diameter larger than at the ends of the threads.

Abstract: A process to control the delivery of a single screw compressor comprising a screw meshing with two pinion wheels and rotatable inside a casing. A channel with obturating means is provided to connect the high pressure orifice pertaining to a one pinion-wheel and the low pressure orifice. Auxiliary orifices are arranged to connect the various zones of the casing exposed to pressure with the low pressure orifice, said auxiliary orifices being provided with obturating devices. Said orifices are sequentially opened to diminish the delivery, starting from the orifice located near the low pressure orifice. First, the orifices pertaining to the first pinion wheel are sequentially opened. Then, the channel connecting the high pressure orifice of the first pinion and the low pressure orifice is opened. Then, the auxiliary orifices pertaining to the second pinion are sequentially opened.

Abstract: A process to supercharge and control a compressor comprising a single screw co-operating with at least two pinions in order to constitute as many partial compressors as there are pinions, such partial compressors operating in parallel and one of them at least being provided with a delivery control device, wherein the supercharging flow is injected into only one of the partial compressors and the delivery of the compressor is controlled from maximal delivery by reducing at first the deliveries of those partial compressors into which the supercharging flow is not injected.

Abstract: A tool having only an end cutting-edge carries out a first movement of penetration into a screw blank so as to produce a groove having flanks substantially parallel to the pinion axis. The tool-holder is angularly displaced with respect to the spindle which carries the screw blank. A second movement of tool penetration takes place while the relative displacement is progressively reduced in order to obtain an inclined flank which produces a V-shaped profile. The screw is intended to form part of a compression and expansion machine and to cooperate with at least one pinion having V-form teeth.

Abstract: A compressor or expansion machine for fluids comprises a rotor, a casing at least partially surrounding the rotor and a pinion which is rotatable about an axis which is not parallel to the rotor axis. The rotor is provided with helical threads having crests which are disposed on a surface of revolution about the rotor axis and the pinion has teeth which engage between two adjacent threads of the rotor to form a compression or expansion chamber in conjunction with the casing, the flanks of the pinion teeth comprising at least three skewed surfaces which intersect in at least two edges.

Abstract: The method of energy conversion consists in burning a fuel in an oxidizing gas in order to admit the combustion gases into an expansion machine for delivering mechanical energy, in previously compressing the oxidizing gas in a positive-displacement compressor driven by the expansion machine, in injecting into the compressor a sealing and/or lubricating auxiliary liquid which is continuously cooled and separated from the compressed gas, then re-injected into the compressor. The auxiliary liquid is cooled by vaporization of water and the steam produced is entrained in the stream of compressed oxidizing gas.

Abstract: This invention relates to a rotary fluid machine (e.g. a compressor) of the single screw type, the single screw cooperating with rotary toothed gate rotors to define fluid-filled chambers whose volumes vary as the screw rotates. The invention is concerned with the provision of two or more capacity-regulating valves provided for the chambers of such a machine, the operating members of such valves being arranged such that one member can be moved independently of the other or others.

Abstract: A tool having only an end cutting-edge carries out a first movement of penetration into a screw blank so as to produce a groove having flanks substantially parallel to the pinion axis. The tool-holder is angularly displaced with respect to the spindle which carries the screw blank. A second movement of tool penetration takes place while the relative displacement is progressively reduced in order to obtain an inclined flank which produces a V-shaped profile. The screw is intended to form part of a compression and expansion machine and to cooperate with at least one pinion having V-form teeth.

Abstract: A single screw, gate rotor machine in which compressible fluid is fed to the machine through a low pressure inlet and exhausts through a higher pressure outlet, in which an unloading valve is provided in the casing adjacent to the high pressure side of the gate rotor, or each gate rotor where there are two gate rotors.

Abstract: In a double-acting rotary compressor having two compression spaces each constituted by at least one variable-volume compression chamber which is put into communication first with the suction enclosure and then with the discharge enclosure, the power consumption at low delivery is reduced by causing the two compression spaces to discharge in parallel into a common duct in the vicinity of maximum delivery and connecting the spaces in series for deliveries below a predetermined value by joining the outlet of the first space to the second space at a point at which the compression chamber is already isolated from the suction enclosure.

Abstract: A machine for compressing or expanding fluids in which a globoidal worm, having a plurality of threads with crests circumscribed by a surface generated by a rectilinear line and in meshing engagement with at least one toothed pinion, cooperates with a casing having at least one low pressure port and at least one high pressure port located in the immediate vicinity of the pinion. Each of the pinion teeth is provided with two substantially rectilinear flanks, the flank located on the side of the pinion nearest the low pressure port when one tooth is engaged in the worm being longer than the flank of the same tooth which is located nearest the high pressure port.

Abstract: The crest of a projecting helical thread formed on a rotor is located on a surface of revolution with respect to the rotor axis and cooperates in a fluid-tight manner with a stationary casing which surrounds the rotor. At least one toothed sealing wheel is engaged with the rotor thread so as to rotate about a transverse axis with respect to the rotor axis and one face of each tooth which is in mesh with the thread is exposed to the high-pressure fluid. The portions of each tooth-flank which are adjacent to said face are portions of surface of revolution and include those zones of the flanks which come into contact with the thread during rotational motion.

Abstract: A device is provided, such as a compressor, expansion machine, pump, hydraulic motor and the like, to vary the pressure of a fluid. Such device comprises a rotor having a toroidal surface and provided with a plurality of threads, a casing having symmetry of revolution about the axis of said rotor and adapted to cooperate with the crests of the threads of said rotor, and at least a pinion whose teeth come into mesh with said threads.