TURBO COMPRESSOR

Abstract

A first centrifugal impeller and a second centrifugal impeller are arranged in such an orientation that back sides of the first centrifugal impeller and the second centrifugal impeller face to each other. Bearings are cylindrical roller bearings and a thrust bearing. The cylindrical roller bearings are arranged at two axially spaced supporting positions respectively, and support a radial load applied to the rotating shaft. The thrust bearing supports a thrust load applied to the rotating shaft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing a structure of a conventional turbo compressor;

FIG. 2 is a view showing an arrangement of a refrigerating circuit of a turbo refrigerator to which a turbo compressor in accordance with the present invention is applied;

FIG. 3 is a view showing a structure of a turbo compressor in accordance with a first embodiment of the present invention;

FIG. 4 is a partial enlarged view showing the structure of the turbo compressor in accordance with the first embodiment of the present invention;

FIG. 5 is a view showing a shape of an inner scroll chamber and an outer scroll chamber in a cross section taken along a line A-A in FIG. 4;

FIG. 6 is a partial enlarged view showing a structure of a turbo compressor in accordance with a second embodiment of the present invention; and

FIG. 7 is a partial enlarged view showing a structure of a turbo compressor in accordance with a third embodiment of the present invention.

Claims

1. A turbo compressor comprising: a rotating shaft provided in a housing and rotationally driven by a drive source;bearings rotatably supporting the rotating shaft; anda first centrifugal impeller and a second centrifugal impeller arranged on the rotating shaft to be axially spaced from each other,wherein the first centrifugal impeller and the second centrifugal impeller are arranged in such an orientation that back sides of the first centrifugal impeller and the second centrifugal impeller face to each other, andthe bearings are cylindrical roller bearings and a thrust bearing, the cylindrical roller bearings being arranged at two axially spaced supporting positions respectively and supporting a radial load applied to the rotating shaft, the thrust bearing supporting a thrust load applied to the rotating shaft.

2. A turbo compressor comprising: a rotating shaft provided in a housing and rotationally driven by a drive source;bearings rotatably supporting the rotating shaft; anda first centrifugal impeller and a second centrifugal impeller arranged on the rotating shaft to be axially spaced from each other,wherein the first centrifugal impeller and the second centrifugal impeller are arranged in such an orientation that back sides of the first centrifugal impeller and the second centrifugal impeller face to each other, andthe bearings support the rotating shaft at two axially spaced supporting positions, and at least one of the bearings is a deep groove ball bearing.

3. The turbo compressor according to claim 1, wherein the first centrifugal impeller and the second centrifugal impeller are arranged in this order from one end side of the rotating shaft, the rotating shaft is structured such that a driving force is transmitted thereto at a position on the opposite side from the first centrifugal impeller with respect to the second centrifugal impeller in the axial direction, andthe bearing supporting the rotating shaft at one of the supporting positions is arranged between the first centrifugal impeller and the second centrifugal impeller, and the bearing supporting the rotating shaft at the other of the supporting positions is arranged on the opposite side from the first centrifugal impeller with respect to the second centrifugal impeller in the axial direction.

4. A turbo compressor comprising: a rotating shaft provided in a housing and rotationally driven by a drive source;bearings rotatably supporting the rotating shaft; anda first centrifugal impeller and a second centrifugal impeller arranged on the rotating shaft to be axially spaced from each other,wherein the first centrifugal impeller and the second centrifugal impeller are arranged in this order from one end side of the rotating shaft in such an orientation that back sides of the first centrifugal impeller and the second centrifugal impeller face to each other,the rotating shaft is structured such that a driving force is transmitted thereto at a position on the opposite side from the first centrifugal impeller with respect to the second centrifugal impeller in an axial direction, andthe bearing supporting the rotating shaft at one of the supporting positions is arranged between the first centrifugal impeller and the second centrifugal impeller, and the bearing supporting the rotating shaft at the other of the supporting positions is arranged on the opposite side from the first centrifugal impeller with respect to the second centrifugal impeller in the axial direction.

5. The turbo compressor as claimed in claim 1, further comprising a speed increasing mechanism for transmitting the rotational driving force output from the drive source to the rotating shaft while increasing the rotational speed output by the drive source, wherein the speed increasing mechanism is arranged between the second centrifugal impeller and the bearing supporting the rotating shaft at the other of the supporting positions.

6. The turbo compressor according to claim 2, wherein the first centrifugal impeller and the second centrifugal impeller are arranged in this order from one end side of the rotating shaft, the rotating shaft is structured such that a driving force is transmitted thereto at a position on the opposite side from the first centrifugal impeller with respect to the second centrifugal impeller in the axial direction, and

7. The turbo compressor as claimed in claim 2, further comprising a speed increasing mechanism for transmitting the rotational driving force output from the drive source to the rotating shaft while increasing the rotational speed output by the drive source, wherein the speed increasing mechanism is arranged between the second centrifugal impeller and the bearing supporting the rotating shaft at the other of the supporting positions.

8. The turbo compressor as claimed in claim 3, further comprising a speed increasing mechanism for transmitting the rotational driving force output from the drive source to the rotating shaft while increasing the rotational speed output by the drive source, wherein the speed increasing mechanism is arranged between the second centrifugal impeller and the bearing supporting the rotating shaft at the other of the supporting positions.

9. The turbo compressor as claimed in claim 4, further comprising a speed increasing mechanism for transmitting the rotational driving force output from the drive source to the rotating shaft while increasing the rotational speed output by the drive source, wherein the speed increasing mechanism is arranged between the second centrifugal impeller and the bearing supporting the rotating shaft at the other of the supporting positions.

10. The turbo compressor as claimed in claim 6, further comprising a speed increasing mechanism for transmitting the rotational driving force output from the drive source to the rotating shaft while increasing the rotational speed output by the drive source, wherein the speed increasing mechanism is arranged between the second centrifugal impeller and the bearing supporting the rotating shaft at the other of the supporting positions.