Figure 1 shows an axial section through the compressor, figure 2 A radial cross-section is shown in, and it is embodied in this embodiment as a linear compressor with a housing 21 that houses a hollow cylindrical bearing bush 23 that defines a working chamber 22. The bearing bushing 23 is assembled by connecting an odd number, in this embodiment, 5, ring-shaped or hollow cylindrical elements 24, 25, 26, 27, 28, which are arranged in the axial direction. The directions follow each other. The two outer elements 24, 28 and the central element 26 in the device each have an annular recess on the front face 29 opposite to each other, and the end regions of the elements 25, 27 located between the annular recesses engage Into the annular recess. The elements 24 to 28 all have exactly the same inner diameter, so that their inner surfaces are flush-connected. The elements 25, 27 each have an outer diameter smaller than the outer diameter of the adjacent elements 24, 26, 28, so that the bearing bush 23 has two circumferential channels 30 on its outer surface, each circumferential channel At the height of elements 25,27.
 The outer surfaces of the elements 24, 26, 28 are held radially without play, so as to be in contact with the inner surface of the tubular housing 21, and frictionally engaged in the axial direction (by, for example, shrinking the housing 21 to the element 24, 26, 28) Fix the outer surfaces of the elements 24, 26, 28 in place. The elements 25, 27 are successively fixed in the recesses of the elements 24, 26, 28 at appropriate positions through a play-free joint.
 As in image 3 It can be seen that the elements 25, 27 and a plurality of radially positioned grooves 32 are arranged on their front end faces 29, the inner end of each groove 32 is supplied into the working chamber 22, and the outer end transitions Into the groove 33, the groove 33 extends axially across the element 25 or, depending on the specific situation, the outer surface of the element 27. The width and depth of the grooves 32, 33 are at most tens of microns; their length can be several millimeters. When the elements 24 to 28 have been connected together, the axial grooves 33 will each extend from the recess of the element 24, 26 or 28. The channels 32, 33 will work with the opposite front end faces 29 of the elements 24, 26, 28, thus forming supply channels through which the channel 30 communicates with the working chamber 22.
 The piston 34 is arranged in the working chamber 22 in an axially movable manner. The diameter of the piston 34 is about 30 mm, and is about 10 to 20 μm smaller than the inner diameter of the elements 24 to 28, so that when the piston 34 is concentrically arranged with respect to the bearing bush 23, the gap 35 with a width of 5 to 10 μm separates the piston 34 It is circumferentially separated from the inner surface of the bearing bush 23. Some of the grooves 32 are fed into the gap 35.
 The working chamber 22 is sealed at the end surface by a spring plate 36 welded to the circumferential flange of the housing 21. One-way valves 37, 38 are formed in the spring plate 36, which allow flow in directions opposite to each other. The cover 39 is mounted on the side of the spring plate 36 which faces away from the working chamber 22, and the two chambers 40, 41 are recessed in the cover. The movement of the piston 34 away from the spring plate 36 sucks gas out of the chamber 40 and through the valve 38 into the working chamber 22. The next movement of the piston 34 toward the spring plate 36 compresses the gas in the working chamber 22 and finally presses it into the chamber 41 through the valve 38.
 The drilled compressed gas supply lines 42, 43 extend from the chamber 41 to the channel 30 through the spring plate 36 and the tubular housing part 31. The overpressure in the chamber 41 will expand into the channel 30 via the compressed gas supply lines 42, 43, so that the gas will flow back into the working chamber 22 through the grooves 33, 32, and thereby form an air cushion that guides the piston 34 It does not come into contact with the bearing bush 23.
 Obviously, a compressor with a reduced length or a reduced number of supply passages can be easily realized by omitting the elements 26, 27 and directly inserting the element 25 into the recess in the element 28. A compressor having a longer length and/or a larger number of supply passages is similarly provided by inserting additional element pairs 26, 27 and generating compressed gas supply lines respectively supplying the synthesis channel 30.
 Figure 4 shows an enlarged axial section through one of the elements 25,27. It can be seen that in the section, the depth of the groove 33 extending across the outer surface of the elements 25, 27 decreases with their distance from the front face 29, from which the depth of the groove starts increase. The shape of the groove has two advantages: on the one hand, it can produce grooves 32, 33 in the connecting process by molding with the aid of a mold (not shown) that rests against the front face 29 of the element 25, 27 On the other hand, the unnecessary sudden deflection of the airflow at the transition between the grooves 32, 33 will cause turbulence, and will eliminate the pressure drop through their confluence at an obtuse angle.
 Figure 5 shows a second embodiment through a pneumatic bearing, a section similar to that shown in Figure 1, this embodiment is distinguished from the embodiment shown in Figure 1 by two mutually independent realizable features . The first feature is the presence of sealing gaskets 44, which are rectangular in cross-section and are each located in a recess in the elements 24, 26, 28, for example covering the front face 29 of the joining element 25, 27. The sealing gasket 44 is slightly plastically deformable, so that when it does not penetrate into the groove 32 and narrows its cross-section, they can still make the wide area, low-amplitude between the front faces of the components opposite to each other. The unevenness is equal, and thus prevents the compressed gas from passing through the gap located away from the grooves 32, 33 from one of the channels 30 to the working chamber 22.
 The second feature is that the elements 24 to 28 forming the bearing bushing 23 are housed in a slotted cylindrical bushing 45, which in turn is applied to the inner surface of the tubular housing portion 31. Because the groove 46 in the bush 45 is aligned with the channel 47 in the spring plate 36, and is firmly sealed at the end facing away from the spring plate 36 by, for example, a synthetic resin plug 48, the channel 30 of the bearing bush 23 Each of them does not have to be made accessible through a separate bore 40 or (depending on the specific situation) 41, the compressed gas from the chamber 41 can reach all the channels 30 of the bearing bushing 23, as shown in Figure 1 Shown. If the bearing bush 23 has been assembled from a large number of elements following each other, the embodiment shown in Fig. 5 will therefore be particularly advantageous.
 Figure 7 A schematic diagram of a driving unit that can be used to drive the oscillating movement of the piston 36 is shown. The unit includes two E-shaped yokes 1 with three arms 3, 4, 5 arranged opposite to each other in pairs. The mutually facing ends of the arms 3, 4, 5 each form a pole shoe 7 that defines an air gap 2. The excitation coils 8 are attached around the center arms 4, respectively. The current can be applied to the two excitation coils 8 through a control circuit, and the current directions in the two excitation coils 8 are respectively established, so that the pole shoes 7 of the center arm 4 opposite to each other form different magnetic poles. The pole shoes of the outer arms 3 and 5 form magnetic poles, each of which is different from the magnetic pole formed by the adjacent central arm 4.
 In the air gap 2, the armature 10 is suspended by two springs 11, for example at the top and bottom reversal points (or Figure 7 The right-hand and left-hand reversal points in the schematic shown in the figure are movable in a reversing manner. The position of the armature 10 at the top reversal point is shown by a continuous line, and its position at the bottom reversal point is shown by a dashed line. Each spring 11 is a leaf spring, which is stamped out of a piece of metal plate and has a plurality of zigzag arms 12. The arms 12 of the spring 11 each extend as a mirror image of each other from the center point of the action on the armature 10 to the suspension point 13 on a fixed frame (not shown), to which the yoke 1 and the compressor are anchored On a fixed frame. The spring 11 will be difficult to deform in the longitudinal direction of the armature 10 and in any direction orthogonal thereto due to this embodiment, so that the armature 10 will be reversibly guided in the longitudinal direction of the armature 10.
 The substantially rod-shaped armature 10 includes a four-pole permanent magnet 14 in its central area. However, the magnet 14 will be centrally positioned in the air gap 2, and when the spring 11 is in the relaxed position, the maximum magnetic flux density between its left and right hand poles in FIG. 1 will extend centrally through the central arm 4, In the relaxed position, the arm 12 of each spring 11 is positioned substantially in the same plane, and when current is applied to the coil 8, the armature 10 will be deflected to the left or right depending on the direction of the current.