Globoid-worm compressors

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. According to the invention, the device is mainly characterized in that the teeth of said pinion are cut in a surface having symmetry of revolution about the rotation axis of said pinion and are inclined to said axis at an angle smaller than 90 degrees, in that milled slots are formed in said casing to enable said teeth to pass through the latter and to engage with said rotor and in that ports for admission and discharge of said fluid are provided on each side of said rotor, the ports for passage of the fluid on the high pressure side being located in the immediate vicinity of said pinion.

What I claim is: 
     
       1. A device for varying the pressure of a fluid such as a compressor, pressure regulator, pump, hydraulic motor and the like and comprising a rotor having a toroidal surface .Iadd.generated by a circular arc lying in a plane disposed at an angle to the meridianal plane of said surface, said toroidal surface being .Iaddend.provided with a plurality of projecting threads whose crests are adapted to cooperate with a casing having symmetry of revolution with respect to the axis of said rotor and to come into mesh with the teeth of at least one pinion, characterized in that the teeth of said pinion are cut in a surface having symmetry of revolution with respect to the axis of rotation of said pinion and are inclined to said axis at an angle which is smaller than 90 degrees, that milled slots are formed in said casing so as to permit said teeth to pass through this latter and to engage with said rotor and that ports for the admission and discharge of fluid are provided on each side of said rotor, the ports for the passage of fluid on the high-pressure side being located in the immediate vicinity of the aforesaid pinion. 
     
     
       2. A device in accordance with claim 1, characterized in that the teeth of the pinion are cut in a cylinder of revolution about the axis of rotation of said pinion. 
     
     
       3. A device in accordance with claim 2, characterized in that the teeth of the pinion are adapted to cooperate with a rotor in which the thread crests are limited by a cylindrical surface. 
     
     
       4. A device in accordance with claim 3, characterized in that the axis of rotation of the pinion is inclined with respect to the axis of rotation of the rotor in such a manner as to ensure that the pinion is located at a greater distance from the axis of the rotor on the side corresponding to the high-pressure openings than on the side corresponding to the low-pressure openings through which the fluid passes. 
     
     
       5. A device in accordance with claim 4, characterized in that the mean plane which is tangent to the cylindrical surface of the pinion teeth in the zone in which said teeth come into mesh with the threads of the rotor is substantially parallel to the axis of rotation of said rotor. 
     
     
       6. A device in accordance with claim 2 and in which the crests of the rotor threads are limited by a substantially plane surface and adapted to cooperate with a flat center, characterized in that the axis of rotation of the pinion is inclined with respect to the axis of rotation of the rotor so that the pinion is located at a greater distance from the rotor in the region which is adjacent to the axis of said rotor than in the peripheral region of said rotor. 
     
     
       7. A device in accordance with claim 6 and in which the rotor is provided with two threaded portions adapted to cooperate with flat symmetrical casings, characterized in that each threaded portion is adapted to engage with at least one pinion whose axis of rotation is inclined with respect to the plane of the corresponding casing. 
     
     
       8. A device in accordance with claim 7 and in which each of the threaded portions of the rotor is adapted to engage with two pinions each having a cylindrical set of teeth, characterized in that the axes of rotation of the pinions are symmetrical with respect to the rotor shaft and are inclined at equal angles with respect to a plane which passes through the rotor shaft. 
     
     
       9. A device in accordance with claim 8, characterized in that the pinions which cooperate with the opposite faces of the rotor are parallel in pairs, the pinion of each pair which cooperates with one face of the rotor being intended to displace the fluid by means of the internal side of its set of teeth whilst the other pinion of each pair which cooperates with the other face of the rotor is intended to displace the fluid by means of the external side of its set of teeth. .[.10. A device in accordance with claim 8, characterized in that the pinions which cooperate respectively with the two opposite faces of the rotor are mounted symmetrically with respect to the central plane of symmetry of the rotor and that the fluid is displaced by the same sides of the sets of teeth of all the pinions..]. 
     
     
        1. A device in accordance with claim 7, characterized in that the casings comprise cylindrical portions which are concentric with the rotor and penetrate respectively into the upper and lower portions of said rotor, said cylindrical portions being provided with ports through which the 
     
     
        fluid on the high-pressure side is intended to pass. 12. A device in accordance with claim 6, characterized in that the casing is provided with ports through which the fluid on the high-pressure side is intended to 
     
     
        pass. 13. A device in accordance with claim 12, characterized in that the ports formed in the casing are located on the inside of the pinion and 
     
     
        communicate with a duct formed in the shaft of said pinion. 14. A device in accordance with claim 6, characterized in that the teeth of the pinion have a trapezoidal profile whose short side is located at the outer 
     
     
        extremity of the teeth. 15. A device in accordance with claim 6, characterized in that it comprises elastic members for applying the pinions against the rotor in a direction parallel to the axis of rotation 
     
     
        of said pinions. 16. A device in accordance with claim 1, characterized in that the opening for the passage of fluid on the low-pressure side is adapted to communicate at the same time with all the chambers which are defined by adjacent threads of the rotor and the opening for the passage of fluid on the high-pressure side is adapted to communicate with those 
     
     
        chambers which are sealed off by the teeth of a same pinion. 17. A device in accordance with claim 1, characterized in that the openings for the passage of fluid on the low-pressure side and high-pressure side are each respectively in communication with all the chambers which are defined by adjacent worm threads and are located along a generator-line of the casing and that the zone of the casing which is adapted to cooperate with the rotor in fluid-tight manner and which is located between consecutive openings on the low-pressure side and high-pressure side extends over a spatial interval which is greater than the distance between two crests of 
     
     
        consecutive threads. 18. A device in accordance with claim 1, characterized in that the radially inner face and radially outer face of each pinion tooth, with respect to the axis of rotation of the pinion, are each inclined to said axis at angles smaller than 90°.