Axial locking device for turbine blades

Abstract

An axial locking device for turbine blades includes a turbine disk, a plurality of blades, and a plurality of pins. The turbine disk is arranged in a cylindrical shape and has a recessed avoidance groove along its axial end surface. The turbine disk is also provided with a plurality of through grooves, which are arranged at intervals along the outer peripheral wall of the turbine disk and extend along the axial direction of the turbine disk. The turbine disk is also provided with a plurality of through holes, each of which is arranged at intervals on the groove wall of the avoidance groove along the circumference of the avoidance groove, and each through hole connects the corresponding through groove with the avoidance groove respectively; the plurality of blades each include a main body portion and a matching portion which are arranged oppositely, and each matching portion is also recessed with a limiting groove, and each limiting groove corresponds to each through hole one by one; the plurality of pins pass through the corresponding through holes and extend into the corresponding limiting groove to lock each blade along the axial direction of the turbine disk. With such an arrangement, the pins can meet the circumferential locking requirements between the blades and the turbine disk, and the pins are easy to process and manufacture, which can reduce the manufacturing cost.

Description

Technical Field

[0001] The present invention relates to the technical field of turbines, and in particular to an axial locking device for turbine blades. Background Art

[0002] The turbine rotor of a gas turbine is usually composed of a turbine disc, turbine blades and corresponding locking devices. The turbine blades adopt a fir-tree-shaped tenon structure, which cooperates with the corresponding fir-tree-shaped tenon groove on the turbine disc to bear the centrifugal force when the turbine rotor rotates at high speed. At the same time, the tenon groove on the turbine disc also limits the turbine blades in the circumferential direction. Therefore, the turbine disc and the turbine blades need to be designed with corresponding locking devices to withstand the axial force of the blades when the turbine is running and prevent the blades from axial displacement.

[0003] At present, the commonly used locking devices are: one is to install a locking plate by slotting at the bottom of the mortise and tenon structure, such as the locking plate structure used in patent CN208778046U. This method requires the customization of a special locking plate. At the same time, the locking plate is heavy, and its centrifugal force is superimposed on the blade, increasing the load of the fir-tree-shaped mortise and tenon. The other is to install an annular baffle by opening annular grooves on the end faces of turbine blades and turbine disks, such as the baffle structure used in patent EP 2808489B1. In this method, the centrifugal force of the baffle is concentrated on the local position of the blade, which is easy to cause stress concentration at that location and reduce the fatigue life of the turbine blade. Therefore, improvement is urgently needed. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide an axial locking device for turbine blades, aiming to provide a locking device that is simple to manufacture and can meet the requirements of turbine blades to withstand axial forces.

[0005] An axial locking device for turbine blades, comprising a turbine disk, a plurality of blades and a plurality of pins; wherein the turbine disk is arranged in a cylindrical shape and has a avoidance groove concavely arranged along its axial end surface, the turbine disk is also provided with a plurality of through grooves, the plurality of through grooves are arranged at intervals along the outer peripheral wall of the turbine disk and extend along the axial direction of the turbine disk, each of the through grooves also penetrates the two end surfaces in the axial direction of the turbine disk, the two groove walls of each of the through grooves are convexly provided with a first limiting rib, the turbine disk is also provided with a plurality of through holes, each of the through holes is arranged at intervals along the circumference of the avoidance groove on the groove wall of the avoidance groove, and each of the through holes respectively locks the turbine disk. The corresponding through grooves are connected to the avoidance grooves; multiple blades include a main body and a matching part that are arranged opposite to each other, and each matching part has two first plug-in grooves, which are arranged on the two side surfaces of the matching part and extend along the axial direction of the turbine disk. The matching part is inserted into the through groove along the axial direction of the turbine disk so that the two first limiting ribs are plugged and matched with the corresponding first plug-in grooves. Each matching part is also recessed with a limiting groove, and each limiting groove corresponds to each through hole one by one; multiple pins pass through the corresponding through holes and extend into the corresponding limiting grooves to lock each blade along the axial direction of the turbine disk.

[0006] As a preferred embodiment, each of the pins is loosely matched with the corresponding through hole, and each of the pins is loosely matched with the two groove walls of the corresponding limiting groove.

[0007] As a preferred embodiment: the two groove walls of each through groove are also protruding with a second limiting rib, the two second limiting ribs are spaced apart from the two first limiting ribs, each matching part also has a second plug-in groove, the two second plug-in grooves are arranged on the two side surfaces of the matching part and are spaced apart from the two first plug-in grooves, the matching part is inserted into the through groove along the axial direction of the turbine disc so that the two second limiting ribs are plug-matched with the corresponding second plug-in grooves.

[0008] As a preference, each of the pins is a tapered pin, and each of the through holes is a tapered hole.

[0009] Preferably, each of the pins has a locking section and a riveted section that are relatively arranged, the outer diameter of the riveted section is larger than the outer diameter of the locking section, each of the locking sections is used to extend into the corresponding limiting groove, and each of the through holes also includes an avoidance opening, and each of the avoidance openings is used to accommodate the riveted section.

[0010] Preferably, one end of each pin adjacent to the avoidance groove is riveted to the corresponding through hole.

[0011] By adopting the above scheme, the beneficial effects of the present invention are as follows: the locking device uses pins to fix the blades and the turbine disk. The pins can withstand the axial force of the blades and meet the circumferential locking requirements between the blades and the turbine disk. The pins are simple to process and manufacture, and do not require customization, which can reduce manufacturing costs. In addition, there is a gap between the pins and the blades. Under the action of aerodynamic force, the blades produce reciprocating vibrations near their equilibrium positions. The friction at each connection dissipates part of the vibration energy, reduces the vibration stress of the blades, and can also extend the fatigue life of the blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural exploded view of an embodiment of an axial locking device for turbine blades in the present invention;

[0013] Figure 2 It is a structural cross-sectional view of an embodiment of an axial locking device for turbine blades in the present invention;

[0014] Figure 3 It is a structural cross-sectional view of an embodiment of an axial locking device for turbine blades in the present invention;

[0015] Figure 4 It is a structural cross-sectional view of an embodiment of the present invention in which the pin is a tapered pin;

[0016] Figure 5 It is a structural cross-sectional view of an embodiment of the present invention in which the pin is a stepped pin.

[0017] Explanation of the reference numerals: 100, turbine disk; 100a, avoidance groove; 100b, through groove; 100c, through hole; 110, first limiting rib; 120, second limiting rib; 200, blade; 210, main body; 220, matching part; 220a, first plug-in groove; 220b, second plug-in groove; 220c, limiting groove; 300, pin; 310, locking section; 320, riveting section. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principles of the present invention, several improvements and modifications may be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0019] like Figures 1 to 3 As shown, an axial locking device for a turbine blade 200 comprises a turbine disk 100, a plurality of blades 200 and a plurality of pins 300; wherein the turbine disk 100 is arranged in a cylindrical shape and has an avoidance groove 100a recessed along its axial end face, and the avoidance groove 100a is arranged in a circular groove body.

[0020] The turbine disk 100 is also provided with a plurality of through grooves 100b, which are arranged at intervals along the outer peripheral wall of the turbine disk 100 and extend along the axial direction of the turbine disk 100. Each through groove 100b also penetrates the two end surfaces of the turbine disk 100 in the axial direction. Both groove walls of each through groove 100b are convexly provided with a first limiting rib 110, and the two first limiting ribs 110 are also extended along the axial direction of the turbine disk 100. The turbine disk 100 is also provided with a plurality of through holes 100c, each through hole 100c is arranged on the groove wall of the avoidance groove 100a at intervals along the circumferential direction of the avoidance groove 100a, and each through hole 100c connects the corresponding through groove 100b with the avoidance groove 100a.

[0021] It should be noted that the axial direction of each through hole 100 c is arranged at an angle with the axial direction of the turbine disk 100 to ensure that each through hole 100 c can be connected to the corresponding through groove 100 b.

[0022] Multiple blades 200 all include a main body portion 210 and a matching portion 220 that are relatively arranged. Each matching portion 220 is used to be plugged and matched with the corresponding through groove 100b. Each matching portion 220 has two first plugging grooves 220a. The two first plugging grooves 220a are arranged on the two side surfaces of the matching portion 220 and extend along the axial direction of the turbine disk 100. The matching portion 220 is plugged into the through groove 100b along the axial direction of the turbine disk 100 so that the two first limiting ribs 110 are plugged and matched with the corresponding first plugging grooves 220a. In this way, when the turbine disk 100 drives each blade 200 to rotate, each blade 200 can be plugged and matched with the two first limiting ribs 110 and the two first plugging grooves 220a without being disengaged along the radial direction of the turbine disk 100.

[0023] Furthermore, each mating portion 220 is also recessed with a limiting groove 220c, and each limiting groove 220c corresponds one-to-one to each through hole 100c; a plurality of pins 300 pass through the corresponding through holes 100c and extend into the corresponding limiting groove 220c to lock each blade 200 along the axial direction of the turbine disk 100.

[0024] With such arrangement, the axial force generated by the blade 200 during rotation is transmitted to the pin 300 through the groove wall of the limiting groove 220c, and the pin 300 transmits the axial force to the turbine disk 100 through the through hole 100c of the turbine disk 100, that is, each blade 200 can be locked by the corresponding pin 300 along the axial direction of the turbine disk 100, so that each blade 200 can be fixed relative to the turbine disk 100.

[0025] In order to facilitate each pin 300 to extend into the corresponding limiting groove 220c through the corresponding through hole 100c, each pin 300 is loosely matched with the corresponding through hole 100c. In this way, each pin 300 is convenient to extend into the limiting groove 220c through the corresponding through hole 100c.

[0026] It should be noted that each pin 300 also cooperates with the gap between the two groove walls of the corresponding limit groove 220c, so that after each limit groove 220c is aligned with the corresponding through hole 100c, the pin 300 can extend into the limit groove 220c, thereby limiting the blade 200 along the axial direction of the turbine disk 100; and there is a gap between the pin 300 and the limit groove 220c of the blade 200. Under the action of aerodynamic force, the blade 200 generates reciprocating vibration near its equilibrium position, and the friction at each connection dissipates part of the vibration energy, reduces the vibration stress of the blade 200, and can also extend the fatigue life of the blade 200.

[0027] In order to further ensure that when the turbine disk 100 drives the blades 200 to rotate, the blades 200 will not disengage in the radial direction of the turbine disk 100, in this embodiment, the two groove walls of each through groove 100b are also convexly provided with a second limiting rib 120, and the two second limiting ribs 120 are spaced apart from the two first limiting ribs 110, and each matching portion 220 also has a second plug-in groove 220b, and the two second plug-in grooves 220b are arranged on the two side surfaces of the matching portion 220 and are spaced apart from the two first plug-in grooves 220a, and the matching portion 220 is inserted into the through groove 100b along the axial direction of the turbine disk 100 so that the two second limiting ribs 120 are plugged and matched with the corresponding second plug-in grooves 220b. With such arrangement, the two first limiting ribs 110 and the two second limiting ribs 120 are plugged into and matched with the corresponding two first plug-in grooves 220a and the two second plug-in grooves 220b, so that the blade 200 can be stably plugged into the turbine disk 100, preventing the blade 200 from detaching in the radial direction of the turbine disk 100.

[0028] It is worth noting that in order to prevent each pin 300 from falling off from the side of the corresponding through hole 100c adjacent to the avoidance groove 100a after being installed in the corresponding through hole 100c, one end of each pin 300 adjacent to the avoidance groove 100a is riveted to the corresponding through hole 100c, so that one end of each locking pin adjacent to the avoidance groove 100a forms an interference fit with the corresponding through hole 100c, thereby preventing the locking pin from falling off from the through hole 100c. In addition, there are many tools for riveting the locking pin, such as special tools such as riveting guns and riveting machines, and the riveting tools are not specifically limited here.

[0029] In one embodiment, Figure 4As shown, each pin 300 is a tapered pin 300, and each through hole 100c is a tapered hole, so that the outer peripheral wall of the pin 300 forms a guiding inclined surface, which facilitates the pin 300 to pass through the through hole 100c and align with the corresponding limiting groove 220c.

[0030] In another embodiment, Figure 5 As shown, each pin 300 has a locking section 310 and a riveting section 320 that are relatively arranged. The outer diameter of the riveting section 320 is larger than the outer diameter of the locking section 310. Each locking section 310 is used to extend into the corresponding limiting groove 220c. Each through hole 100c also includes an avoidance opening, and each avoidance opening is used to accommodate the riveting section 320. With this arrangement, the outer diameter of the riveting section 320 is larger, and the interference fit area between the pin 300 and the through hole 100c can be increased after riveting, so that the pin 300 is not easy to fall off from the through hole 100c.

Claims

1. An axial locking device for a turbine blade, characterized in that: It comprises a turbine disk (100), a plurality of blades (200) and a plurality of pins (300); wherein: The turbine disk (100) is provided in a cylindrical shape and has a avoidance groove (100a) concavely provided along its axial end surface. The turbine disk (100) is also provided with a plurality of through grooves (100b). The plurality of through grooves (100b) are arranged at intervals along the outer peripheral wall of the turbine disk (100) and extend along the axial direction of the turbine disk (100). Each of the through grooves (100b) is also provided through two axial directions of the turbine disk (100). end surface, both groove walls of each through groove (100b) are convexly provided with a first limiting rib (110), the turbine disc (100) is further provided with a plurality of through holes (100c), each of the through holes (100c) is arranged on the groove wall of the avoidance groove (100a) at intervals along the circumferential direction of the avoidance groove (100a), and each of the through holes (100c) respectively connects the corresponding through groove (100b) with the avoidance groove (100a); The plurality of blades (200) each comprises a main body (210) and a matching portion (220) which are arranged opposite to each other, each matching portion (220) having two first plugging grooves (220a), the two first plugging grooves (220a) being arranged on two side surfaces of the matching portion (220) and extending along the axial direction of the turbine disk (100), the matching portion (220) being plugged into the through groove (100b) along the axial direction of the turbine disk (100) so that the two first limiting ribs (110) are plugged and matched with the corresponding first plugging grooves (220a), each matching portion (220) is also provided with a recessed limiting groove (220c), and each limiting groove (220c) corresponds one-to-one to each through hole (100c); The plurality of pins (300) pass through the corresponding through holes (100c) and extend into the corresponding limiting grooves (220c) to lock each blade (200) along the axial direction of the turbine disk (100); Each of the pins (300) is clearance-matched with the corresponding through hole (100c), and each of the pins (300) is also clearance-matched with two groove walls of the corresponding limiting groove (220c); Each of the pins (300) is a tapered pin (300), and each of the through holes (100c) is a tapered hole; Each of the pins (300) comprises a locking section (310) and a riveting section (320) which are arranged opposite to each other, the outer diameter of the riveting section (320) is larger than the outer diameter of the locking section (310), each of the locking sections (310) is used to extend into a corresponding limiting groove (220c), and each of the through holes (100c) further comprises an avoidance opening, and each of the avoidance openings is used to accommodate the riveting section (320); One end of each pin (300) adjacent to the avoidance groove (100a) is riveted to the corresponding through hole (100c).

2. The axial locking device for turbine blades according to claim 1, characterized in that: The two groove walls of each through groove (100b) are also convexly provided with a second limiting rib (120), and the two second limiting ribs (120) are arranged at intervals with the two first limiting ribs (110). Each matching portion (220) also has a second plug-in groove (220b), and the two second plug-in grooves (220b) are arranged on the two side surfaces of the matching portion (220) and are arranged at intervals with the two first plug-in grooves (220a). The matching portion (220) is inserted into the through groove (100b) along the axial direction of the turbine disk (100) so that the two second limiting ribs (120) are plugged and matched with the corresponding second plug-in grooves (220b).

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