US2453284A - Rotary pump or rotary compressor - Google Patents

Description

Nov. 9, 1948. A. K. e. B. TbRNBoRG ROTARY IUMP OR ROTARY COMPRESSQR Filed April 6, 1944 In I) can/$01 41. K. 6'. .B. Tcj'z nb ory Patented Nov. 9, 1948 SEARUH more ROTARY PUMP OR ROTARY COMPRESSOR Algot Karl Gustaf Birger Tiirnborg, Nassjo, Sweden Application April 6, 1944, Serial No. 529,741 In Sweden May 13, 1943 1 Claim. (01. 103-126) The present invention relates to rotary pumps or rotary compressors such as comprise a housing, cylindrical chambers in said housing and rotors located in said hollow spaces and coopcrating in pairs with one another and with the circular walls of the chambers.

According to the invention, the rotors are provided with a circumference extending in a general Way spirally and with offsets which form transitions between different radial distances determining the spiral pitch. Further the rotors are provided with portions which join onto or substantially onto the circular walls of the chambars.

The portions joining onto the circular walls of the chambers extend directly from the offsets and are preferably of such a length that the half or approxmately the half of the inlet and the outlet of the pump, compressor, etc., at the junction between the chambers is shut oil when said portions are passing the Junction, thus a certain temporary shutting-off action with regard to the inlet and the outlet being effective.

A plurality of rotors may be placed cw side by side on each rotor shaft for the purpose of forming romrgups having rotors cooperating in pairs. In this case, the offsets are preferably so arranged in the different rotor groups-as to be peripherically displaced in relation to each other in order to operate approximately in the same manner as the cogs of a gear. By this, a transmission of motion from-one rotor shaft to the other is rendered possible, without it being necessary to arrange any particular toothed gear or the like between the shafts.

However, in case the pump or the compressor is provided with only one pair of rotors, the drive from one rotor shaft to the other may advantageously be transmitted by means of a toothed gear or the like.

An embodiment of the invention is illustrated in the accompanying drawing, in which Figures 1 and 2 show two rertical sections through the intended pump or compressor, said sections being taken at right angles to each other.

Mounted in the housing I are, as mentioned above, two rotors cooperating with one another and with the wall of the housing and each.consisting of a disc 2 and 3, respectively, or the like, the circumference of which discs extends in a general way spirally. Said rotors are disposed in chambers 4 and 5 which have a circular sectional profile and are bounded by and communicate with each other at a point situated right between those shafts 6 and I to which the rotors are keyed. The shafts 6 and l are mounted in covers 8 and 9 located on either side of the midportion of the housing I. Secured to the shaft 1, which forms the driving shaft of the pump or compressor, is a pinion III, which meshes with a pinion ll mounted on the shaft 6, so that the rotatory motion is transmitted from the shaft 1 to the shaft 6. In this way, the rotors 2 and 3 will evidently be endowed with a positive rotatory motion in directions of rotation opposite to each other. The pinions I0 and II are disposed in chambers corresponding to the before-mentioned chambers 4 and 5.

The inlet and the outlet of the pump or compressor are disposed at that point at which the chambers 4 and 5 communicate with each other. The inlet and the outlet form together a passage l2 which extends right across the housing I while passing the above-mentioned junction between the chambers 4 and 5.

As previously mentioned, the rotors 2 and 3 are provided with offsets H! which form transitions between difierent radial distances determining the spiral pitch of the rotors. These offsets may be designed substantially in correspondence with a tooth flank so that they will cooperate with each other during the rotatory motion of the rotors approximately in the same manner as the tooth flanks of a pair of pinions, but this shaping and cooperation is not absolutely necessary. Besides, according to a certain realization it is more advantageous if said offsets do not cooperate directly with each other but pass the junction between the chambers at a certain mutual distance from each other, thus the frictional action between the oflsets being eliminated. Said mutual distance between the offsets may be positively maintained by that the engagement of the pinions l0 and H with each other has, in advance, been adjusted in view of this or, in other words, that each offset is peripherically displaced in relation to a corresponding tooth flank.

The rotors 2 and 3 are, as already mentioned, provided along their circumferences with portions circular in side elevation. These portions, which in the drawing are designated by I4. extend directly from the ofisets and are of such a length that they shut on the half or approximately the half of the inlet and of the outlet at the junction between the chambers, when they pass said junction, thus also a certain temporary closing action with regard to the inlet and the outlet being brought about.

The embodiment described above and shown in the drawing is'only intended to illustrate the principle of the invention, within the limits of which many other realizations may be applied. For exgnple, it may be mentioned that each rotor may be provided with more than one ofiset, more than one circular portion, that the toothed gear may be replaced by a belt or chain drive, that several rotors may be mounted coaxially on each rotor shaft 6 and 1, respectively, etc.

As compared With rotary pumps and rotary compressors of previously known kinds, the pump or compressor according to the present invention brings inter alia the advantage that it is extremely simple and free from surfaces causing difliculties or pressing a great accuracy in being treated. Furthermore, no surfaces are present, which are exposed to heavy wear, nor occurs any appreciable loss of power in consequence of friction. Finally, a very intense eifect of suction and pressure is obtained, whereby the pump or compressor becomes particularly adapted to be used as a high pressure pump or compressor. Moreover, the efiect of suction and pressure of the pump or compressor is comparatively equable, due to the fact that the cooperating rotors of each pair of discs operate alternately, i. e. one rotor brings about an eiiect of suction, while the other exerts an effect of pressure, and vice versa.

The pump or compressor may, of course. operate by diiierent kinds of medium under pressure.

I claim:

In a rotary pump or rotary compressor the combination of a housing, communicating chambers in said housing, rotors in the shape of discs having portions of their peripheries in the form REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 20,796 Holley July 6, 1858 31,597 Hardy et a1. Mar. 5, 1861 1,233,599 Nue'bling July 17, 1917 1,846,692 Schmidt Feb. 25, 1932 FOREIGN PATENTS Number Country Date 878 Great Britain Apr. 5, 1860 382,953 Great Britain Nov. 10, 1932 749,899 France May 15, 1933 OTHER REFERENCES Theoretische Kinematik Braunschweig, Germany, of 1875, Plate VIII.

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