Turbine blade tip shroud and tension center damper with connecting and contact angle

Abstract

comprising a turbine blade (72, 98) designed to be supported on a turbine or runner wheel: a blade profile section (76) extending radially with respect to a longitudinal axis (92) of the impeller and comprising a leading edge, a trailing edge, a pressure side (84) and a suction side (86); and at least one mantle extending in opposite circumferential directions, the mantle having a first armor (34, 62, 66, 90; 46, 58, 70, 94) designed to engage with a second armor (46, 58, 70, 94; 34, 62, 66, 90) on a mantle extending circumferentially from an adjacent turbine blade (72, 98), the first armor (34, 62, 66, 90; 46, 58, 70, 94) being defined by a surface section whose circumferential position increases with increasing radius from the longitudinal axis (92); wherein the at least one jacket has a first tip jacket (32, 56, 60, 64, 68, 74) at a radially outer end of the turbine blade (72, 98); wherein the tip mantle (32, 56, 60, 64, 68, 74) is formed with a Z-notched edge on each of its two opposite sides, which are designed to engage with similar Z-notched edges on adjacent tip mantles (32, 56, 60, 64, 68, 74), wherein each Z-notched edge comprises two side sections and the first armor plate (34, 46, 58, 62, 66, 70) which is arranged between the side sections of the Z-notched edge to form the Z-notch shape, wherein the side sections of the Z-notched edge are straight in a radial direction; wherein the first armor (34, 46, 58, 62, 66, 70) of the first tip mantle (32, 56, 60, 64, 68, 74) is formed by a flat surface section which is angled in a radial direction relative to a radial plane extending radially from the longitudinal axis (92) of the wheel and is angled in an axial direction relative to the longitudinal axis (92) of the wheel; wherein the first tip mantle (32, 56, 60, 64, 68, 74) has a radially projecting rib (36) on a radial outer surface of the tip mantle (32, 56, 60, 64, 68, 74), wherein the first armor plating (34, 46, 58, 62, 66, 70) extends in opposite directions from the radially projecting rib (36) and encompasses one end of the radially projecting rib (36); and wherein the first armor layer (34, 46, 58, 62, 66, 70) extends to a U-shaped curve (38) of the Z-notched edge, which is arranged between the first armor layer (34, 46, 58, 62, 66, 70) and one of the side sections of the Z-notched edge.

Description

GENERAL STATE OF THE ART

[0001] The invention relates generally to turbomachinery and in particular to circumferential support arrangements for the blade profile sections of a series of blades or turbine blades mounted on a turbine runner.

[0002] Turbine blades or vanes are often supported at two points along the radial length of the blade or vane profile section. More precisely, the radially outer tips of the blades or vanes engage with individual tip sleeves, while span section or span center sleeves (sometimes called span center dampers) may be provided at points between the radially inner and outer ends of the blade profile sections, engaging with similar span center dampers on adjacent blades.

[0003] Turbine blade tip jackets feature a characteristic called "armoring," which is the contact surface on each jacket that engages with a similar contact surface or armoring on an adjacent jacket. The current tip jacket armoring design is a flat surface oriented straight in a radial direction (see Fig. 1 and Fig. 2) The tip jackets support the blades during turbine operation by keeping them in the correct orientation and counteracting excessive movement due to torsional forces applied to the rotating blades, while also acting as dampers against unwanted blade vibrations. Some tip jackets exhibit known Z-notch designs, where the armor or contact surfaces extend along adjacent, multi-angled edges. These often prove to be life-limiting points for the blades, as they are subjected to high stresses due to jacket deflection and load transfer between adjacent blades. Overlap is another major problem with turbine blade tip jackets, caused by the uneven displacement of the pressure-side and intake-side tip jacket protrusions.

[0004] Similarly, the mating armor plates or contact surfaces between adjacent clamping center sleeves or dampers are flat and aligned radially. Clamping center sleeves are particularly susceptible to overlaps and excessive vibrations, which can also limit their service life.

[0005] Therefore, there is a need for an interface between blades both where the tip skins are located and where the span mid-skins are located, which can reduce or eliminate the aforementioned problems in terms of load, overlap and vibration.

[0006] JP 2002-89 203 A discloses a turbine blade with a blade profile section and a tip jacket extending from the radially outer end of the blade profile section in opposite circumferential directions, wherein the tip jacket has a scuff or contact surface formed by a flat surface section angled in a radial direction relative to a radial plane extending radially from a longitudinal axis of the impeller, such that its circumferential position increases with increasing radius from the longitudinal axis. In one embodiment, span center jacket sections are further formed on the blade profile section, projecting in the circumferential direction to engage with span center jacket sections of adjacent impeller blades.

[0007] JP H02- 40 002 A discloses a turbine blade with a blade profile section and a tip jacket which is formed on its circumferentially opposite sides with Z-notched edges which engage with similar Z-notched edges on adjacent tip jackets at matching contact surfaces.

[0008] JP 2012- 180 764 A discloses a turbine blade with armor plating between contact areas of the mantles of the root, the span center and the tip.

[0009] Based on this, it is an object of the invention to create a turbine blade and a turbine runner with multiple turbine blades that reduce or eliminate the above-mentioned problems relating to load, overlap and vibration.

[0010] To solve these problems, a turbine blade with the features of independent claim 1 and a turbine impeller with the features of dependent claims 5 and 7 have been provided. Particularly preferred embodiments of the invention are the subject of the dependent claims. BRIEF DESCRIPTION OF THE INVENTION

[0011] In one aspect of the invention, a turbine blade designed to be supported on a turbine or impeller comprises: a blade profile section extending radially with respect to a longitudinal axis of the impeller and having a leading edge, a trailing edge, a pressure side, and a suction side; at least one jacket extending in opposite circumferential directions, the jacket having a first armor plate designed to engage with a second, counterpart armor plate on a jacket extending circumferentially from an adjacent turbine blade; the first armor plate being defined by a surface section whose circumferential position varies with increasing radius from the longitudinal axis. The at least one jacket has a first tip jacket at a radially outer end of the turbine blade.The tip mantle is formed with a Z-notched edge on each of its two opposite sides, designed to engage with similar Z-notched edges on adjacent tip mantles. Each Z-notched edge comprises two side sections and the first armor plate arranged between the side sections of the Z-notched edge to form the Z-notch shape. The side sections of the Z-notched edge are straight in a radial direction. The first armor plate of the first tip mantle is formed by a flat surface section angled in a radial direction relative to a radial plane extending radially from the longitudinal axis of the wheel and angled in an axial direction relative to the longitudinal axis of the wheel.The first tip mantle has a radially projecting rib on a radial outer surface of the tip mantle, with the first armor extending in opposite directions from the radially projecting rib and encompassing one end of the radially projecting rib. The first armor extends to a U-shaped curve of the Z-notched edge, which is located between the first armor and one of the side sections of the Z-notched edge.

[0012] The aforementioned at least one shell of each turbine blade may further comprise a first span center shell section projecting from one side of the turbine blade and a second span center shell section projecting from the opposite side of the turbine blade, wherein the first and second span center shell sections are arranged radially between the inner and outer ends of the blade profile section of the turbine blade.

[0013] The aforementioned first armoring of each turbine blade can be aligned at a first acute angle in a range of about 2 to about 15 degrees in one of two opposite directions with respect to the radial plane extending radially from the longitudinal axis and along a centerline of the turbine blade.

[0014] The aforementioned first acute angle of each turbine blade can be in a range that is essentially between 5 and 10 degrees.

[0015] In a further aspect of the invention, a turbine impeller is provided to which several turbine blades are attached, each turbine blade comprising: a blade profile section, wherein the blade profile section has a leading edge, a trailing edge, a pressure side, and a suction side; and adjacent turbine blades belonging to the multiple turbine blades, which can engage with one another along contact surfaces provided on tip or span center sleeves fixed to the blade profile sections, the contact surfaces being inclined in two angular relationships to enable relative movement along their contact surfaces. The tip or span center sleeves have a tip sleeve at a radially outer end of each turbine blade.The tip mantle is formed with a Z-notched edge on each of its two opposite sides, which engage with similar Z-notched edges on adjacent tip mantles. Each Z-notched edge comprises two side sections and a contact surface arranged between the side sections of the Z-notched edge to form the Z-notch shape. The side sections of the Z-notched edge are straight in a radial direction. The contact surface of the tip mantle is formed by a planar surface section that is angled in a radial direction relative to a radial plane extending radially from the longitudinal axis of the impeller and is also angled in an axial direction relative to the longitudinal axis of the impeller.The tip mantle has a radially projecting rib on a radial outer surface of the tip mantle, the first contact surface extending in opposite directions from the radially projecting rib and encompassing one end of the radially projecting rib. The contact surface extends to a U-shaped curve of the Z-notched edge, which is located between the contact surface and one of the side sections of the Z-notched edge.

[0016] Movement in an angular relationship can be made possible by varying the circumferential position of the contact surfaces with increasing radius, thereby creating a first inclination angle.

[0017] The contact surfaces of each turbine impeller mentioned above can have a second angle of inclination in relation to the longitudinal axis of the turbine impeller when viewed from above.

[0018] The first inclination angle can be positive or negative with respect to a reference plane.

[0019] The aforementioned adjacent turbine blades of each turbine runner can engage with each other at both the tip and the span center surfaces.

[0020] The first tilt angle can be in the range of 2 to 15 degrees on any side of a radial reference plane extending along a centerline of the turbine blade.

[0021] This first angle can be in the range of 5 to 10 degrees.

[0022] In a further aspect of the invention, a turbine impeller is provided to which several turbine blades are attached, each turbine blade comprising: a blade profile section, wherein the blade profile section has a leading edge, a trailing edge, a pressure side and a suction side; adjacent turbine blades which can be engaged with one another along two first paired contact surfaces provided on tip sleeves fixed at the outer ends of the blade profile sections of adjacent turbine blades, and two second paired contact surfaces provided on span center sleeves fixed at the pressure and suction sides of the blade profile sections of the adjacent turbine blades, wherein at least one of the two contact surfaces on the tip sleeves or the span center sleeves is inclined in two directions.This creates at least two degrees of freedom of movement for meshing turbine blades at the interface between the contact surfaces forming at least one pair. The tip of each turbine blade is formed with a Z-notched edge on each of its two opposite sides, which engage with similar Z-notched edges on adjacent tip surfaces, each Z-notched edge comprising two side sections and a contact surface arranged between the side sections of the Z-notched edge to form the Z-notch shape, the side sections of the Z-notched edge being straight in a radial direction. The contact surface of each turbine blade's tip is formed by a planar surface section extending radially in a radial direction relative to a radial plane extending radially from the longitudinal axis of the impeller.is angled and is angled in an axial direction relative to the longitudinal axis (92) of the impeller. The tip of each turbine blade has a radially projecting rib on a radial outer surface of the tip, the first contact surface extending in opposite directions from the radially projecting rib and encompassing one end of the radially projecting rib. The contact surface extends to a U-shaped curve of the Z-notched edge, which is located between the contact surface and one of the side sections of the Z-notched edge.

[0023] The aforementioned first and second contact surfaces, each forming a pair, of each turbine impeller vary in the circumferential direction with an increasing radius, measured from a central axis of the impeller.

[0024] The first and second contact surfaces, each forming a pair, can be inclined at an angle of approximately 2 to approximately 15 degrees with respect to a radial reference plane extending along a centerline of the turbine blade.

[0025] The contact surfaces of each turbine impeller mentioned above can be straight.

[0026] The surfaces can define a multi-angled edge.

[0027] These and other aspects, advantages and characteristic features of the invention will become clear from the following detailed description in conjunction with the drawings mentioned below. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a top view of a known Z-notched turbine blade tip mantle and shows a positive-locking engagement with an adjacent tip mantle, which is shown as a dashed line. Fig. 2 is a sectional view along line 2-2 in Fig. 1; Fig. Figure 3 is a top view of a shovel tip mantle according to a first illustrative but not limiting embodiment of the invention; Fig. Figure 4 is a perspective view of a contact surface section of a tip jacket according to the invention and shows positive and negative inclination angles; Fig. Figure 5 is a detailed top view of the interlocking contact surfaces of adjacent lace sheaths according to the invention with a negative angle of inclination; Fig. Figure 6 is a detailed top view of the interlocking contact surfaces of adjacent lace sheaths according to the invention with a positive angle of inclination; Fig. Figure 7 is a perspective view of a turbine blade equipped with tension center sleeves or dampers, according to a further illustrative but not limiting embodiment of the invention; Fig. 8 is a partial top view of the in Fig. 7 adjacent span center sections shown, but also shows the respective blade profile sections of adjacent turbine blades; Fig. Figure 9 is a partial side view of the [image / structure] in Fig. 8 illustrated span center sleeves; and Fig. 10 is a perspective partial view of the in Fig. 8 and Fig. 9 adjacent span center sleeves shown, which are separated from each other here to show the connection angles of the respective contact surfaces of the span center sleeves. DETAILED DESCRIPTION OF THE INVENTION

[0028] Fig. Figure 1 shows an example of a conventional turbine blade tip mantle design. In this example, adjacent blade tip mantles 10, 12 are attached to the radially outer ends of respective blade profile sections of adjacent turbine blades. The tip mantles 10, 12 have armor plates or contact surfaces 14, 16 that engage with each other during turbine operation. With reference to mantle 10, shown with a solid line, the contact surface or armor plate 14 is located between edge sections 18 and 20, which together form a general Z-shape. Tip mantles of this general design are often referred to as "Z-notched" mantles. The contact surfaces 14 and 16 lie in a radial plane that is substantially perpendicular to the radially outer surfaces 21, 23 of the respective tip mantles.In other words, the armor plates or contact surfaces 14, 16 are essentially perpendicular to a tangent at the radially outer edge of the circumferentially arranged row of blades (blade profile sections 24, 26 of turbine blades 28, 30, which are fixed to a (not shown) impeller, are in . Fig. (1 partially shown), which is drawn to intersect the radial centerline of the turbine blade at an angle of 90°. Examples of contact surface designs as described can be found in US 5,522,705 A, US 6,402,474 B1, and US 7,001,152 B2.

[0029] Although not specifically shown, it should be clarified that typical clamping center sleeves or dampers have similar contact surfaces lying in a radial plane perpendicular to a tangent to the outer edge of the row of blades mounted on the impeller.

[0030] It has now been shown that modifying the traditional, radially oriented armor plating or contact surface sections of adjacent blade tip mantles offers advantages. More specifically, it has been shown that angling the armor plating or contact surfaces in the radial direction improves the tip mantle's ability to reduce Z-notch loads and / or overlap.

[0031] It has been found that a similar armoring or contact surface design in span center jackets or span section jackets reduces the vibration of turbine blades at the span center point. Tip jackets and span center jackets are described below according to illustrative, but not limiting, embodiments of the invention. LACE COATS

[0032] According to an illustrative, but not limiting, embodiment of the invention, the armor plates or contact surfaces of adjacent turbine blades remain essentially parallel, but are inclined in the radial direction. The angle and direction of inclination depend on design requirements, such as the shape of the tip plates and the specific problem to be solved, e.g., Z-notch loading; overlap, damping efficiency, or frequency tuning.

[0033] More precisely, and initially with reference to Fig. 3 The blade tip mantle 32 has a Z-groove design on opposite sides of the mantle, designed to engage, at least partially, with similar mantles on adjacent turbine blades. As described below, the illustrated armor or contact surface section 34 of the mantle 32 has a margin on each side of a radially projecting rib 36 and extends in a generally U-shaped curve 38, but it should be clarified that the contact surface section may further extend in any direction from the rib 36, depending on specific applications. At the end 40 of the mantle 32, the contact surface section 34 is undercut in a radial direction, as indicated by the dotted line 42.In other words, the contact surface is inclined at a negative angle with respect to the upper edge of the mantle in a radially inward direction, such that the contact surface section 34 is no longer perpendicular to a tangent of the impeller. At the opposite end 44 of the mantle 32, the contact surface section 46 is inclined in the opposite radially inward direction, as indicated by the solid line 48. It should be noted that in a circumferentially extending row of similar turbine blades with similar tip mantles, the ends 40 of the mantle 32 engage at an end like the end 44 of an adjacent tip mantle. Thus, the contact surface sections remain substantially parallel to each other but are at an angle to a radial plane extending from the axis of the impeller.In simplified terms, a wedge of contact surface material is "removed" from the armor plating of one mantle end to create a negative angle of inclination and "added" to an adjacent armor plating to create a positive angle of inclination. This allows the adjacent armor platings to remain essentially parallel, but along a radially inclined plane. The contact surface section of each tip mantle can also be described by its circumferential position along the armor plating or contact surface, which varies with an increasing radius measured from the central or longitudinal axis of the wheel.

[0034] By tilting the armor or contact surface sections, both radial and circumferential components of a sliding movement are permitted at the interface of the tip jackets. This differs from the armor or contact surface designs of the prior art, where relative movement at the interface is only possible in a radial direction. Thus, the present invention creates an additional degree of freedom of movement at the interface between adjacent tip jackets.

[0035] As stated above, the tilt angle of the contact surfaces can vary in both the positive and negative directions. The tilt angle, and whether it is positive or negative, can vary depending on the specific application. Angles between 2° and approximately 15°, and preferably 5° and 10°, in either a positive or negative direction are intended to improve peak jacket performance by reducing Z-notch loads and overlap, while also enabling better frequency tuning through adjustment of the tilt angles.Regarding the overlap, the armor plating of the tip jackets can be inclined so that the overhang with a higher radial displacement lies on the lower side, so that in operation the side with the least displaced overhang holds the displacement of the transition of the other side, thus maintaining armor plating contact throughout operation.

[0036] A representation of negative and positive inclination angles for the armor plating or contact surfaces is shown in Fig. Figure 4 illustrates this. More precisely, the armor plating or contact surface 50, shown with solid lines, represents the current practice as described in Figure 4. Fig. Figure 2 is shown. According to an illustrative, but not limiting, embodiment of the invention, the armor plating or contact surfaces are inclined with respect to a radial reference plane at an angle of -5° or an angle of +5°.

[0037] Fig. Figure 5 shows an illustrative implementation. The tip mantle 56 is formed with an armor or contact surface 58 with a positive angle of inclination and forms the counterpart to an adjacent tip mantle 60, which is formed with an armor or contact surface 62 with a complementary negative angle of inclination.

[0038] Fig. Figure 6 shows an opposite or reversed configuration, where the tip mantle 64 is formed with an armor or contact surface 66 with a negative angle of inclination and an adjacent mantle 68 is formed with an armor or contact surface 70 with a positive angle of inclination.

[0039] Note that the inclination of the contact surfaces described above is equally applicable to other mantle designs, i.e., those with straight edges or angled edges other than Z-notched edges. In other words, the contact surfaces could be straight along the entire contact line and aligned with the rotor axis, or they could have one or more angles with respect to that axis. Straight contact surfaces are discussed in more detail in the following description of span center mantles.

[0040] In all cases, the tilt angle and tilt direction can be defined to meet design requirements. CENTER SHELL OR DAMPER

[0041] In Fig. Figure 7 shows a turbine blade 72 with a tip mantle 74 at a radially outer end of the blade section 76 of the turbine blade and a span center mantle 78 arranged between the radially inner and outer ends of the blade section. Since the span center mantle 78 actually comprises two discrete mantles 80, 82 projecting from the pressure and suction sides 84, 86 of the blade section ( Fig. 8) It may be appropriate to refer to span center-shell sections 80, 82 of each blade profile. It has been shown that a contact surface arrangement with connection and contact angles for span center-shells or shell sections also reduces vibrations by providing an additional degree of freedom of movement at the contact surface boundary, essentially as described above.

[0042] In an illustrative, but not limiting, embodiment with respect to clamping center shells, the contact surface angle is inclined in two directions, i.e., in a radial direction and an axial direction. Thus, considering the clamping center shell interface between a pair of adjacent turbine blades 72, 98 in a top view with reference to Fig. Figure 8 shows that a shell section projecting laterally from the pressure side 84 of the blade profile section 76 is formed with a straight contact surface 90, which forms an angle alpha with respect to a longitudinal axis of the rotor, shown at 92. The armor or contact surface 90 is shown in engagement with an armor or contact surface 94 on the shell section 96 of an adjacent turbine blade 98. This aspect of the contact surface design is not new in itself. However, the contact surface boundary is also radially angled, as shown in Fig. 9 and Fig. Figure 10 shows an angle beta with respect to a radial plane indicated at 100. This radial inclination is similar to the radial inclination and tip-shell contact surface boundary described above. The angles α and β can be adjusted to optimize the damping behavior of the clamping center shell or damper and can also range from 2 to approximately 15 degrees (or more), depending on the specific application.

[0043] For both tip and center clamping sleeves, the invention improves the service life of the components with only minor modifications to the sleeve geometry. This reduces the likelihood of forced operational downtime due to resonance or overlap.

[0044] Although various embodiments are described herein, it is clear from the description that various combinations of elements, modifications, or improvements can be made by a person skilled in the art and are within the scope of the invention. Furthermore, numerous modifications can be made to adapt a specific situation or a particular material to the teachings of the invention without deviating from its essential scope. Therefore, the invention is not to be limited to the embodiments considered best for carrying out this invention, but rather encompasses all embodiments that fall within the scope of the appended claims.

[0045] A turbine blade designed to be supported on a turbine or impeller has a profile section extending radially with respect to a longitudinal axis of the impeller and comprising a leading edge, a trailing edge, a pressure side, and a suction side. At least one tip shroud extends in opposite circumferential directions, the shroud having a first armor layer designed to engage with a counterpart second armor layer on a shroud of an adjacent turbine blade extending circumferentially. The first armor layer is defined by a surface section that varies circumferentially with an increasing radius measured from the longitudinal axis of the impeller. REFERENCE MARK LIST: 10, 12, 32, 56, 60, 64, 68, 74 Lace coats 14, 16, 34, 50, 58, 62, 66, 70, 90, 94 armor plating or contact surfaces 18, 20 marginal sections 21, 23 radial outer surfaces 24, 26, 76 leaf profile sections 28, 30, 72, 98 turbine blade 32 Shovel tip mantle 36 radially projecting ribs 38 U-shaped curve 40, 44 End 42 dotted line 46 Contact surface section 48 solid line 78 Span center sleeve 80, 82, 96 mantle sections 84, 86 pressure and suction sides 92 Longitudinal axis of the rotor / impeller Level 100, as specified

Claims

[1] Turbine blade (72, 98) designed to be supported on a turbine or runner wheel, comprising: a blade profile section (76) extending radially with respect to a longitudinal axis (92) of the impeller and comprising a leading edge, a trailing edge, a pressure side (84) and a suction side (86); and at least one mantle extending in opposite circumferential directions, the mantle having a first armor (34, 62, 66, 90; 46, 58, 70, 94) designed to engage with a second armor (46, 58, 70, 94; 34, 62, 66, 90) on a mantle extending circumferentially from an adjacent turbine blade (72, 98), the first armor (34, 62, 66, 90; 46, 58, 70, 94) being defined by a surface section whose circumferential position increases with increasing radius from the longitudinal axis (92); wherein the at least one jacket has a first tip jacket (32, 56, 60, 64, 68, 74) at a radially outer end of the turbine blade (72, 98); wherein the tip mantle (32, 56, 60, 64, 68, 74) is formed with a Z-notched edge on each of its two opposite sides, which are designed to engage with similar Z-notched edges on adjacent tip mantles (32, 56, 60, 64, 68, 74), wherein each Z-notched edge comprises two side sections and the first armor plate (34, 46, 58, 62, 66, 70) which is arranged between the side sections of the Z-notched edge to form the Z-notch shape, wherein the side sections of the Z-notched edge are straight in a radial direction; wherein the first armor (34, 46, 58, 62, 66, 70) of the first tip mantle (32, 56, 60, 64, 68, 74) is formed by a flat surface section which is angled in a radial direction relative to a radial plane extending radially from the longitudinal axis (92) of the wheel and is angled in an axial direction relative to the longitudinal axis (92) of the wheel; wherein the first tip mantle (32, 56, 60, 64, 68, 74) has a radially projecting rib (36) on a radial outer surface of the tip mantle (32, 56, 60, 64, 68, 74), wherein the first armor plating (34, 46, 58, 62, 66, 70) extends in opposite directions from the radially projecting rib (36) and encompasses one end of the radially projecting rib (36); and wherein the first armor layer (34, 46, 58, 62, 66, 70) extends to a U-shaped curve (38) of the Z-notched edge, which is arranged between the first armor layer (34, 46, 58, 62, 66, 70) and one of the side sections of the Z-notched edge. [2] Turbine blade (72, 98) according to claim 1, wherein the at least one shell further comprises a first span center shell section (80) projecting from one side of the turbine blade (72, 98) and a second span center shell section (82, 96) projecting from an opposite side of the turbine blade (72, 98), wherein the first and second span center shell sections (80, 82, 96) are arranged radially between the inner and outer ends of the blade profile section (76) of the turbine blade (72, 98). [3] Turbine blade (72, 98) according to claim 1, wherein the first armoring (34, 46, 58, 62, 66, 70) is aligned at a first acute angle in a range of about 2 to about 15 degrees in one of two opposite directions with respect to the radial plane extending radially from the longitudinal axis (92) and along a centerline of the turbine blade (72, 98). [4] Turbine blade (72, 98) according to claim 3, wherein the first acute angle is in a range of substantially 5 to 10 degrees. [5] Turbine impeller to which several turbine blades (72, 98) are attached, each turbine blade (72, 98) having: a blade profile section (76) with a leading edge, a trailing edge, a pressure side (84) and a suction side (86); Turbine blades (72, 98) belonging to several turbine blades (72, 98), adjacent to one another, which can engage with each other along contact surfaces (34, 62, 66, 90; 46, 58, 70, 90, 94) provided on tip or span center shells (32, 56, 60, 64, 68, 74; 78) which are fixed to the blade profile sections (76), wherein the contact surfaces (34, 62, 66, 90; 46, 58, 70, 90, 94) are inclined in two angular relationships in order to allow a relative movement between adjacent tip or span center shells (32, 56, 60, 64, 68, 74; 78) along the contact surfaces (34, 62, 66, 90; 46, 58, 70, 90, 94) to enable; wherein the tip or span center jackets (32, 56, 60, 64, 68, 74; 78) have a tip jacket (32, 56, 60, 64, 68, 74) at a radially outer end of each turbine blade (72, 98); wherein the tip mantle (32, 56, 60, 64, 68, 74) is formed with a Z-notched edge on each of its two opposite sides, which engage with similar Z-notched edges on adjacent tip mantles (32, 56, 60, 64, 68, 74), wherein each Z-notched edge comprises two side sections and a contact surface (34, 46, 58, 62, 66, 70) arranged between the side sections of the Z-notched edge to form the Z-notch shape, wherein the side sections of the Z-notched edge are straight in a radial direction; wherein the contact surface (34, 46, 58, 62, 66, 70) of the tip mantle (32, 56, 60, 64, 68, 74) is formed by a flat surface section which is angled in a radial direction relative to a radial plane extending radially from the longitudinal axis (92) of the impeller and is angled in an axial direction relative to the longitudinal axis (92) of the impeller; wherein the tip mantle (32, 56, 60, 64, 68, 74) has a radially projecting rib (36) on a radial outer surface of the tip mantle (32, 56, 60, 64, 68, 74), wherein the contact surface (34, 46, 58, 62, 66, 70) extends in opposite directions from the radially projecting rib (36) and encompasses one end of the radially projecting rib (36); and wherein the contact surface (34, 46, 58, 62, 66, 70) extends to a U-shaped curve (38) of the Z-notched edge, which is arranged between the contact surface (34, 46, 58, 62, 66, 70) and one of the side sections of the Z-notched edge. [6] Turbine impeller according to claim 5, wherein movement in an angular relationship is enabled by varying the circumferential position of the contact surfaces (34, 62, 66, 90; 46, 58, 70, 90, 94) of the tip and span center shells (32, 56, 60, 64, 68, 74; 78) with increasing radius, thereby generating a first inclination angle. [7] Turbine impeller to which several turbine blades (72, 98) are attached, each turbine blade (72, 98) having: a blade profile section (76), wherein the blade profile section (76) has a leading edge, a trailing edge, a pressure side (84) and a suction side (86); adjacent turbine blades (72, 98) which are connected along two first contact surfaces forming a pair (34, 62, 66; 46, 58, 70), which are provided on tip shells (32, 56, 60, 64, 68, 74) which are fixed to the outer ends of the blade profile sections (76) of adjacent turbine blades (72, 98), and two second contact surfaces forming a pair (90, 94) which are provided on span center shells (78) which are fixed to the pressure and suction sides (84, 86) of the blade profile sections (76) of the adjacent turbine blades (72, 98), can be brought into engagement with each other, wherein at least one pair of the two contact surfaces (34, 62, 66, 90; 46, 58, 70, 94) inclined in two directions at the tip shells (32, 56, 60, 64, 68, 74) or at the span center shells (78), thereby creating at least two degrees of freedom of movement for interlocking turbine blades (72, 98) at the interface between the contact surfaces forming at least one pair: wherein the tip mantle (32, 56, 60, 64, 68, 74) of each turbine blade (72, 98) is formed with a Z-notched edge on each of its two opposite sides, which engage with similar Z-notched edges on adjacent tip mantles (32, 56, 60, 64, 68, 74), wherein each Z-notched edge comprises two side sections and a contact surface (34, 46, 58, 62, 66, 70) arranged between the side sections of the Z-notched edge to form the Z-notch shape, wherein the side sections of the Z-notched edge are straight in a radial direction; where the contact area (34, 46, 58, 62, 66, 70) of the tip mantle (32, 56, 60, 64, 68, 74) of each turbine blade (72, 98) is formed by a flat surface section which is angled in a radial direction relative to a radial plane extending radially from the longitudinal axis (92) of the impeller and is angled in an axial direction relative to the longitudinal axis (92) of the impeller; wherein the tip mantle (32, 56, 60, 64, 68, 74) of each turbine blade (72, 98) has a radially projecting rib (36) on a radial outer surface of the tip mantle (32, 56, 60, 64, 68, 74), wherein the first contact surface (34, 46, 58, 62, 66, 70) extends in opposite directions from the radially projecting rib (36) and encompasses one end of the radially projecting rib (36); and wherein the contact surface (34, 46, 58, 62, 66, 70) extends to a U-shaped curve (38) of the Z-notched edge, which is arranged between the contact surface (34, 46, 58, 62, 66, 70) and one of the side sections of the Z-notched edge.

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