US2535019A - Compressor - Google Patents

Description

Dec. 19, 195o s. J, SSSSSS EN 2,535,019

MMMMMMM 0R Patented Dec. 19, 1950 CMPEESS'OB Sverre Johan Steensen, V. Aker, near Oslo, Norway Application -October 29, i945, Serial No. 625,318 in Norwayaprilv 29, 1942 Section 1, llublic Law 690, August 8, 1946 Patent expires April .29, 1962 1 Claim.

This invention relates to compressors with a piston, which moves eccentrically in relation to the interior cylinder wall, so that its contacting point against the cylinder wall moves constantly around the same. The ordinary construction is that the piston is fastened to a shaft which is located eccentrically relatively to the cylinder and is driven around in the same by means oi' a motor. Consequently the shaft must guided tightly through one head of the cylinder.

vThis construction requires an extreivrnanuiaeture, and already after a very little tear oi the cooperating lsurfaces of piston and cyl'- ly exact inder, a leakage will take place, and the eilicicncy of the compressor will be decreased. Moreover, care must be taken for a tightening by stuillng box at the place where the piston shaft .passes out from the cylinder. Also this will give rise to leakage.

The present invention has for its purpose a construction which is not aillicted with the drawbacks mentioned above, and which is particularly intended to be used in refrigerator cabinets for domestic use. The interior space of the cornpressor itself is hermetically sealed, whereas the motor is located outside the sealed system of compartment and conduits.

It has a simple and eicient execution and consequently is very cheap in manufacture and operation. This is obtained by the use of a strong magnet which rotates in relation to the non-magnetic cylinder outside the latter and thereby causes the contacting point of the magnetic piston to move as stated above.

Thereby a cylindric piston may be placed loosely into a cylinder with a larger diameter, a partition directed towards the center being ixed on the interior cylinder wall and meshing in a radial groove corresponding thereto and made in the piston in order to separate the suction side from the pressure side. Further, a preferably annular rotating magnet with pole shoes is arranged, said shoes travelling with a quite small margin around in the stationary cylinder.

Consequently there are no shafts or eccentrics i and moreover no exact adaptation between the curved surfaces of the piston and the cylinder is required. The end faces of the cylinder may simply be adapted to each other by placing the top and bottom of the cylinder against the end surface of the piston and by soldering them to the periphery of the cylinder casing.

During the rolling or sliding of the piston against the cylinder wall the piston is pressed against this wall and will always provide a good 2 tightening contrary vto whatis the case when the piston is journaled around a pin, because in such a oase it is always necessary to arrange a Small distance which will gradually increase during .the use.

Further it is not necessary to let the said curved surfaces be circle-cylindrical surfaces. r-hey can very `well depart from this shape. although this 4would be less suitable owing to the practical manufacture.

Another embodiment, ywherein the rotor in known manner rotates on a pin arranged eccentrically in the interior of the cylinder and provided with one or `more partitions guided radially in the vpiston and being maintained constantly in contact ywith the cylinder wall, may consist in the rotor oi non-magnetic material rotating loosely on the eccentric pin and the partitions of magnetic material travelling loosely in their grooves acted upon by corresponding rotating magnets arranged outside the apparatus. Also this embodiment permits an hermetical sealing but is nevertheless less suitable.

In the drawing the two embodiments mentioned above are illustrated. Fig. 1 is a cross section through the compressor, and Fig. 2 a corresponding axial longitude section.

The cylinder wall which is made of non-magnetic material is for instance a thin bronze pipe, to which is soldered the endwalls 2, 2 which may be made of steel. One endwall is first soldered fast, whereafter the piston 4 of magnetic material and with a somewhat less diameter is inserted. Then the other wall is placed in position until it is in contact with the piston and is soldered fast in this position. Thereby the compressor itself is ready-mounted.

As will be seen from Fig. 1 the piston, which may have 3 4 mm, less diameter than the cylinder l, and lies loosely within the same, may roll or slide along the inner wall surface of the cylinder, it being coupled together with the cylinder only by the xed wing 3, which forms a partition between the suction and pressure side of the compressor. This wing 3 is fastened to the end-faces of the cylinder. l

The ports 5 and 6 represent the suction and pressure channels, dependent upon the direction of rotation.

Around the cylinder a strong magnet 8 is mounted on a disk 9, which is fastened to the motorshaft IIJ, so that it rotates around the cylinder I with a quite small intermediary space, for instance 0.1 mm. The pole shoes I3 and I4 of the magnet attract the piston 4, so that it will contact strongly against the cylinderwall, and the contacting point will move around according as the magnet rotates.

In this manner two separate compartments are formed, a suction and a pressure compartment.

These compartments increase or decrease in volume according as the magnet rotates, and the contacting point adjacent to the pole shoes of the magnet moves along the periphery, whereby the enclosed gas passes in through one and out from the other one of the ports 5 and 6. The interior of the compressor of course must be supplied with oil for lubricating and tightening the surfaces. The magnet may be an electric magnet with sliding contacts or a permanent magnet.

Of course not the Whole piston 4 need be of magnetic material. It is sufcient that only an exterior cylindric ring is made of such a material, 01 the piston may be annular.

By very strong magnets it might occur' that the pole-shoes attract the piston so strongly against the cylinderwall, that this in spite of the insignicant sliding may give rise to tear or to deformation of the thin-walled cylinder. This may be avoided by arranging inside the cylinder, as shown in Fig. 1, a stationary concentric pin Il and by providing the piston with a bore ll, which is concentric with the piston but eccentric to the cylinder, whereby the attracting force of the magnet will be taken up by the pin I l which in such case must be made exactly.

Besides, it is obvious that the magnet or magnets rotating around the pump housing, may be replaced by a plurality of stationary electromagnets arranged around the housing and the current of which is closed in succession, so that a rotary magnet eld is obtained.

I claim:

A compressor comprising a pump housing having an interior cylindrical space, a cylindrical rotor piston of a diameter diierent from that of interior space of the housing and located loosely and eccentrically within the housing, said piston being at least partly of magnetizable material, means outside the housing for producing a rotary eld of magnetic forces to cause the piston to contact at any time with said wall along an axially directed straight contacting line in rolling along said wall with the contacting line travelling constantly around on the wall in accordance with the rotation of said magnetic eld, an inlet port for the medium to be compressed, an outlet port for the compressed medium, and a partition arranged between the inlet and outlet ports so as to separate at any time the suction space of the pump from the compression space.

SVERRE JOHAN STEENSEN.

REFERENCES CITED The following references are of record in the iie of this patent:

UNITED STATES PATENTS Number Name Date 229,592 Drawbaugh July 6, 1880 1,766,872 Berglund June 24, 1930 2,161,374 Moineau June 6, 1939 2,399,856 Coger May 7, 1946 FOREIGN PATENTS Number Country Date 762,483 France Jan. 22, 1934

Images