1. A compressor unit, comprising: a multistage centrifugal compressor for compressing a gas an electric motor having a stator and a rotor for driving the multistage centrifugal compressor, the rotor being supported by a first and second magnetic radial bearings each magnetic radial bearing being arranged at opposite ends of the rotor and a magnetic thrust bearing arranged adjacent to one of the first or second magnetic radial bearings, the multistage centrifugal compressor and the electric motor being accommodated in a common gastight housing which is provided with a gas inlet and a gas outlet, the stator being accommodated and isolated from the multistage centrifugal compressor in a separate stator space, which is delimited by a toroidally shaped wall section, radially and axially surrounding the stator, of the common gastight housing of the compressor unit, a gastight partition which extends between the stator and the rotor of the electric motor, and a first end wall which extends between the gastight partition and the common gastight housing of the compressor unit and a second end wall arranged opposite the first end wall and configured to isolate the stator from the compressor in cooperation with the gastight partition and the first end wall, wherein the gastight partition extends freely between the stator and the rotor of the electric motor and comprises a material of sufficiently high strength for it to remain clear of the stator and the rotor under working pressures of the gas which may occur inside the common gastight housing, wherein the high-strength material of the gastight partition comprises a fibre-reinforced plastic.
2. A compressor unit according to claim 1, in which the gastight partition comprises an erosion-resistant layer on the rotor side.
3. A compressor unit according to claim 1, in which the gastight partition comprises a gastight layer.
4. A compressor unit according to claim 1, in which the gastight partition comprises a layer of corrosion-free metal.
5. A compressor unit according to claim 1, in which the gastight partition comprises a layer of polyaryl ether ketone.
6. A compressor unit according to claim 1 in which the wall thickness of the gastight partition is greater at the ends than in the middle.
7. A compressor unit according to claim 1, in which the gastight partition and the first and second end walls are separate parts which are connected to one another in a gastight manner by means of one or more sealing rings.
8. A compressor unit according to claim 1, in which the stator space is provided with connections to a cooling unit for supplying and discharging a cooling medium.
9. A compressor unit according to claim 1, in which the gastight partition comprises a separate inner layer and outer layer, on the rotor and stator side, respectively, at least the inner layer having erosion-resistant properties, at least one layer having a high strength and at least one layer being gastight.
10. A method of producing a gastight partition for a compressor unit, the compressor unit comprising a multistage centrifugal compressor for compressing a gas and an electric motor having a stator and a rotor for driving the multistage centrifugal compressor, the rotor being supported by a first and second magnetic radial bearings each magnetic radial bearing being arranged at opposite ends of the rotor and a magnetic thrust bearing arranged adjacent to one of the first and second magnetic radial bearings, the multistage centrifugal compressor and the electric motor being accommodated in a common gastight housing which is provided with a gas inlet and a gas outlet, the stator being accommodated in a separate stator space, which is delimited by a wall section, surrounding the stator, of the common gastight housing of the compressor unit, a gastight partition which extends between the stator and the rotor of the electric motor, and at least one end wall which extends between the gastight partition and the common gastight housing of the compressor unit, wherein the gastight partition extends freely between the stator and the rotor of the electric motor and comprises a material of sufficiently high strength for it to remain clear of the stator and the rotor under working pressures of the gas which may occur inside the common gastight housing, wherein the high-strength material of the gastight partition comprises a cured fibre-reinforced plastic, in which the gastight partition comprises a separate inner layer and outer layer on the rotor and stator side, respectively, at least the inner layer having erosion-resistant properties, at least one layer having a high strength and at least one layer being gastight, the method comprising:
producing the inner layer and outer layer separately, in the form of an inner shell and an outer shell, the external diameter of the inner shell, under the same pressure and temperature, being larger than the internal diameter of the outer shell;
temporarily increasing the diameter of the outer shell by means of gas or liquid pressure, or temporarily reducing the diameter of the inner shell by lowering the temperature of the inner shell, so that it is possible to push the inner shell into the outer shell; and
restoring the diameter of the outer or inner shell by restoring the pressure of the outer shell or restoring the temperature of the inner shell.
11. The multistage centrifugal compressor, the rotor being supported by a first and second magnetic radial bearings each magnetic radial bearing being arranged at opposite ends of the rotor and a magnetic thrust bearing arranged adjacent to one of the first or second two magnetic radial bearings, the multistage centrifugal compressor and the electric motor being accommodated in a common gastight housing which is provided with a gas inlet and a gas outlet, the stator being accommodated and isolated from the multistage centrifugal compressor in a separate stator space, which is delimited by a wall section, radially and axially surrounding the stator, of the common gastight housing of the compressor unit, a gastight partition which extends between the stator and the rotor of the electric motor, and a first end wall which extends between the gastight partition and the common gastight housing of the compressor unit and a second end wall arranged opposite the first end wall and configured to isolate the stator from the compressor in cooperation with the gastight partition and the first end wall, wherein the gastight partition extends freely between the stator and the rotor of the electric motor and comprises a material of sufficiently high strength for it to remain clear of the stator and the rotor under working pressures of the gas which may occur inside the common gastight housing, wherein the high-strength material of the gastight partition comprises a fibre-reinforced plastic, the method comprising:
compressing gas using the compressor unit.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An apparatus for movably supporting a food tray having a center of gravity, said apparatus: comprises:
a substantially stationary base structure;
a support boom which comprises:
a bearing structure movably secured to said base structure;
a platform shaped and dimensioned to support said tray, said platform having a distal section;
a rigid beam having a proximal end portion secured to said bearing structure, and a distal end portion secured to said distal section at a point located distally from said center of gravity;
whereby said platform has a proximal section located proximately to said center which deflects downwardly in response to a sufficient weight of said tray and its contents.
2. The apparatus of claim 1, wherein said platform is secured to said beam in absence of a substantial structural connection between said platform and said beam located proximally from said center of gravity.
3. The apparatus of claim 1, wherein said platform comprises a closed ring having a most distal section secured to said beam.
4. The apparatus of claim 1, wherein said beam comprises a stop surface to prevent deflection of said proximal section beyond a given distance.
5. The apparatus of claim 1, wherein said boom further comprises a handle extending downwardly from a medial portion of said beam.
6. The apparatus of claim 5, wherein said handle is camouflaged as a plant appendage.
7. The apparatus of claim 1, wherein said base structure comprises a post having a substantially cylindrical outer surface and wherein said bearing structure rotatably engages said outer surface.
8. The apparatus of claim 7, wherein said bearing structure comprises a sleeve having an axial bore shaped and dimensioned to intimately and rotatably engage said substantially cylindrical outer surface of said post.
9. The apparatus of claim 1, wherein said post defines an interior lumen extending from a top end opening to a bottom end opening, said lumen being shaped and dimensioned to allow passage of an umbrella pole therethrough.
10. The apparatus of claim 1, wherein said base structure consists of an umbrella pole.
11. The apparatus of claim 1, wherein said apparatus further comprises a plurality of said supports booms axially spaced apart upon said post and being independently rotatable.
12. The apparatus of claim 11, wherein said apparatus further comprises a at least one spacer sleeve having an axial bore shaped and dimensioned to intimately and rotatably engage a substantially cylindrical outer surface of said post.
13. The apparatus of claim 1, wherein a top end of said post is threaded.
14. The apparatus of claim 1, which further comprises a top cap comprising a tray supporting pedestal formed thereon.
15. The apparatus of claim 1, wherein said platform is hingedly connected to said beam such that said platform deflects toward said post under the force of a given weight.
16. The apparatus of claim 1, wherein said platform is biased toward a horizontal orientation.
17. In a rotatable food tray support apparatus comprising a support boom movably attached to a standard wherein said boom comprises a rigid beam secured to a platform for supporting a tray having a center of gravity, an improvement which comprises:
said platform being hingedly secured to said beam at a point a greater radial distance form said standard than said center of gravity.