Pelton runner
AssigneeANDRITZ HYDRO GmbH
InventorsBenno Loetscher, Pascal Isler, Stefan Lais
Life of this patent
Estimating the term…
Abstract
A Pelton runner with a wheel disk and separately fabricated buckets (2), which may be cast or made from a solid block of material and secured detachably to the wheel disk (1), fastened by at least one screw (5) or at least one bolt. At least one screw or at least one bolt is designed as an expansion screw (5) or expansion bolt, where the expansion screw (5) or expansion bolt is subjected to controlled pre-stressing, and each bucket (2) has at least one expansion screw (5) or expansion bolt that is arranged perpendicular to the axis of rotation of the wheel disk (1) and secured to the wheel disk (1).
Claims15
A Pelton runner including a wheel disk and separately manufactured buckets, wherein each of the buckets is cast or made from a solid block of material, secured detachably to the wheel disk, and fastened by at least one screw or at least one bolt to the wheel disk,
- wherein the at least one bolt or the at least one screw includes an shaft having a first end section with threads configured to engage a threaded surface in a hole in an outer surface of the wheel or in one of the buckets;
- wherein the shaft of at least one bolt or the at least one screw has a middle section that has a smaller outer diameter than an outer diameter of the first end section and a second end section of the shaft opposite to the first end section;
- wherein a cylindrical bushing is seated both in the hole of the annular wheel disk and the hole in the one of the buckets;
- wherein the shaft of the at least one bolt or the at least one screw extends through a passage in the cylindrical bushing and the middle section of the shaft is covered by the cylindrical bushing while the first and second end sections are outside of the cylindrical bushing;
- wherein the at least one screw or the at least one bolt is subjected to controlled pre-stressing, and
- wherein the at least one screw or the at least one bolt is arranged perpendicular to an axis of rotation of the wheel disk and secured to the wheel disk;
- wherein the at least one screw or the at least one bolt is aligned with a central plane that extends through the wheel disk, and is equally distant from a front surface and a rear surface of the wheel disk, and
- wherein, for each of the buckets, a pair of shear pins are on opposite sides of the at least one screw or the at least one bolt, extend into the bucket and the wheel disk, and are centered on a line perpendicular to the central plane and offset from the at least one screw or the at least one bolt.
A Pelton runner comprising:
- a wheel disk having an outer surface facing radially outward,
- buckets attached to the outer surface of the wheel disk;
- a fastener attaching at least one of the buckets to the wheel disk, wherein the fastener includes a shaft having a first end section with threads which are configured to engage a threaded interior surface of a hole in the wheel disk or a hole in the attached bucket and a second end section opposite to the first end section and a middle section having an outer diameter smaller than outer diameters of the first and second end sections, wherein the fastener is oriented perpendicular to an axis of rotation of the wheel disk and the fastener is in a pre-stressed condition, wherein the fastener is aligned with a central plane, and the central plane extends through the wheel disk, is perpendicular to the axis of rotation, and is equally distant between a front surface and a rear surface of the wheel disk;
- a cylindrical bushing seated in both the hole of the wheel disk and the hole in the at least one bucket, wherein the fastener extends through the bushing, and
- shear pins on opposite sides of the fastener, and extending into the wheel disk and the bucket, wherein the shear pins are aligned centered on a line perpendicular to the central plane and offset from the fastener.
Dependencies are inferred from the claim text.