Nozzle ring for a radial turbine and exhaust gas turbocharger including the same
A nozzle ring for a radial turbine includes a disc-shaped main body having a central opening for passing a shaft therethrough. Additionally, the nozzle ring includes guide vanes disposed circumferentially in a radially outer portion on a first surface of the main body. Two or more bores are provided in a radially inner portion of the main body. Further, a groove is provided in the first surface of the main body, the groove connecting at least two of the two or more bores.
1. A nozzle ring for a radial turbine comprising:
a disc-shaped main body having a central opening for passing a shaft therethrough;
guide vanes disposed circumferentially in a radially outer portion on a first surface of the disc-shaped main body;
two or more bores provided in a radially inner portion of the disc-shaped main body; and
a groove provided in the first surface of the disc-shaped main body, the groove connecting at least two of the two or more bores.
2. The nozzle ring of claim 1 , wherein the groove extends at least partially concentrically around the central opening.
3. The nozzle ring of claim 1 , wherein the groove is a closed-loop.
4. The nozzle ring of claim 1 , wherein the two or more bores are arranged on a first virtual circle line having a first radius R 1 around the central opening, and wherein the guide vanes are arranged on a second virtual circle line having a second radius R 2 around the central opening, wherein R 2 ≥1.5×R 1 .
5. The nozzle ring of claim 1 , wherein the groove has a cross-sectional shape selected from the group consisting of: a rectangular U-shape, a square U-shape, a round U-shape, and a trapezoidal U-shape.
6. The nozzle ring of claim 5 , wherein the groove has one or more rounded edges.
7. The nozzle ring of claim 1 , wherein the groove has a width W and a depth D, the width being larger than or equal to the depth.
8. The nozzle ring of claim 7 , wherein the groove has a width-to-depth ratio W/D of 1≤W/D≤5.
9. The nozzle ring of claim 1 , wherein the groove has a width W and a depth D, the depth being larger than or equal to the width.
10. The nozzle ring of claim 9 , wherein the groove has a depth-to-width ratio D/W of 1≤D/W≤5.
11. The nozzle ring of claim 1 , wherein the groove has a width W of 2 mm≤W≤10 mm and a depth D of 0.4 mm≤D≤10 mm.
12. The nozzle ring of claim 1 , further comprising a mounting flange provided in the radially inner portion on a second surface of the disc-shaped main body, and wherein the two or more bores extend through the mounting flange.
13. The nozzle ring of claim 12 , wherein the mounting flange is integrally formed with the disc-shaped main body.
14. The nozzle ring of claim 1 , wherein the guide vanes are integrally formed with the disc-shaped main body.
15. The nozzle ring of claim 1 , wherein the nozzle ring is an integral one-piece element.
16. The nozzle ring of claim 1 , wherein the two or more bores are configured to receive one or more fasteners, and wherein the two or more bores are arranged with a regular angular spacing around the central opening.
17. The nozzle ring of claim 1 , wherein a second surface of the disc-shaped main body comprises one or more recesses for forming one or more air-filled insulation space(s) when the nozzle ring is mounted to a bearing housing.
18. The nozzle ring of claim 1 , wherein the groove connects all of the two or more bores.
19. An exhaust gas turbocharger comprising:
a turbine housing,
a shaft which is mounted in a bearing housing and on which a turbine wheel with rotor blades is arranged,
an exhaust gas inlet passage formed in the turbine housing upstream of the turbine wheel, and
the nozzle ring according to claim 1 , the nozzle ring fixed to the bearing housing by fasteners extending through the two or more bores.