A rotary machine includes a guide section formed in an annular flow path in communication with a suction volute at an inner circumferential side of the suction volute, at which a plurality of vanes are installed in a circumferential direction, and configured to guide a fluid introduced from the suction volute, and an impeller connected to the guide section in the axial direction and into which the fluid guided by the guide section is introduced. The suction volute has an annular opening section in communication with the guide section at the inner circumferential side, and an inner wall surface extending from the opening section toward the axial direction of the impeller in the axial direction to increase a width dimension in the axial direction and connected to a partition section at an opposite side of the suction nozzle.
1. A rotary machine comprising:
a nozzle configured to introduce a fluid from an outer circumferential side to an inner circumferential side in a radial direction;
a volute having a space in communication with the nozzle at the outer circumferential side and a partition section configured to separate the space in a circumferential direction at an opposite side from a connection section connected to the nozzle with a central axis sandwiched therebetween;
a guide section having a first flow path in communication with the volute at the inner circumferential side of the volute, and a second flow path extending from the inner circumferential side of the first flow path toward a downstream side along the central axis, and being configured to guide the fluid introduced from the volute; and
an impeller connected to the guide section in an axial direction and into which the fluid guided by the guide section is introduced,
wherein the volute comprises:
an annular opening section in communication with the guide section at the inner circumferential side of the space of the volute; and
an inner wall surface extending from the opening section toward the impeller to increase a width dimension in the axial direction of the impeller, the inner wall surface being connected to the partition section, at the opposite side from the connection section with the central axis of the impeller sandwiched therebetween, towards which a dimension in the axial direction gradually decreases,
wherein a plurality of vanes are installed at the first flow path of the guide section and extend toward the second flow path,
wherein the plurality of vanes comprise:
first vanes each having an inner circumferential vane and an outer circumferential vane connected to each other; and
second vanes installed at different positions from those of the first vanes in the circumferential direction, and each only having an outer circumferential vane,
wherein the inner circumferential vanes of the first vanes are disposed nearer to the second flow path than the outer circumferential vanes of the first vanes and the second vanes, and
wherein a vane disposed at the furthest position at an opposite side from the connection section with the central axis sandwiched therebetween is one of the outer circumferential vanes of the second vanes.
2. The rotary machine according to claim 1 , wherein the second vanes are disposed at positions between the first vanes in the circumferential direction.
3. The rotary machine according to claim 1 , wherein the inner circumferential vanes extend in the radial direction,
wherein portions on the inner circumferential side of the outer circumferential vanes of the first vanes and portions on the inner circumferential side of the outer circumferential vanes of the second vanes extend in the radial direction, and
wherein portions on the outer circumferential side of the outer circumferential vanes of the first vanes and portions on the outer circumferential side of the outer circumferential vanes of the second vanes extend in the direction along the flow of fluid introduced into the guide section from the volute.