Support structure, fan and method of assembling a fan

Abstract

The application provides a supporting structure, a fan and an assembling method of the fan. The supporting structure is applied to a fan of an open rotor engine. The fan comprises a hub and a blade. The blade has a blade handle. The supporting structure is assembled on the blade handle. The hub provides an assembling channel. The supporting structure is assembled in the assembling channel so that the blade is supported on the hub. The supporting structure comprises a first bearing and a second bearing. The assembling channel of the hub has an annular protrusion. An outer ring of the second bearing provides an annular step matched with the annular protrusion. In an assembled state, the annular protrusion and the annular step keep an axial distance in an axial direction. In an assembling process state, the annular protrusion is pressed against the annular step so as to eliminate the axial distance. The inner ring and the outer ring of the first bearing provide an assembling distance for rolling elements of the first bearing. The assembling distance is equal to the axial distance. The structure is convenient for quick disassembly or assembly.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, and in particular to a support structure, a fan, and a method for assembling the fan. Background Technology

[0002] Compared to the high-bypass turbofan engines widely used in the civil aviation field, open rotor engines (i.e., propfan engines) have significantly higher bypass ratios, resulting in improved propulsion efficiency and a substantial reduction in fuel consumption. Against the backdrop of the aviation industry's pursuit of carbon neutrality, open rotor engines are receiving increasing attention from engine main contractors. The superior economics of open rotor engines are inseparable from their ultra-large, wide-chord swept blades, but their unique configuration and large blades also create challenges during installation and disassembly. Open fan blades can reach diameters of 4 meters or even larger. Therefore, during packaging and transportation, the blades are typically disassembled into individual pieces or components and transported with the engine body, only to be reassembled upon arrival at the destination. This places high demands on the assemblability of the open fan blade support structure.

[0003] Open-type fan blades involve numerous components during assembly and disassembly. Assembly involves all components in their individual parts, while disassembly requires breaking them down to the component level. This process is time-consuming and inevitably leads to complex assembly procedures, necessitating specialized tooling and increasing costs for both testing and user units. To address these assembly / disassembly difficulties, current solutions typically involve creating openings in the hub and bearing housing to accommodate the rolling elements of the ball bearing.

[0004] However, this design compromises the integrity of the bearing outer ring structure and the hub structure. The rolling elements will experience significant vibrations when passing through the opening, which will have a substantial impact on the strength of the bearing and hub. Furthermore, it requires the design of additional matching plugs and other structures, increasing the structural complexity and cost. Summary of the Invention

[0005] The purpose of this invention is to provide a support structure, a fan, and a fan assembly method that facilitates the assembly and disassembly of the blades.

[0006] One aspect of the present invention provides a support structure for a fan in an open rotor engine. The fan includes a hub and blades, each blade having a shank. The support structure is mounted on the shank, and the hub provides a mounting channel within which the support structure is mounted to support the blades. The support structure includes a first bearing, the inner ring of which presses against the shank, the outer ring of which is mounted on the hub, and rolling elements of which are mounted between the outer and inner rings. The support structure further includes a second bearing, the inner ring of which... The outer ring of the second bearing is pressed against the blade shank, and mates with the hub; the hub has an annular protrusion in the assembly channel; the outer ring of the second bearing provides an annular step that matches the annular protrusion; in the assembled state, the annular protrusion and the annular step maintain an axial distance in the axial direction; in the assembly process state, the annular protrusion presses against the annular step, thereby eliminating the axial distance, so that the inner ring and the outer ring of the first bearing provide an assembly distance in the axial direction for operating the rolling elements of the first bearing; wherein, the assembly distance is equal to the axial distance.

[0007] In one embodiment, the support structure further includes a positioning element connected to the outer ring of the second bearing; the positioning element has an arcuate portion adapted to the rolling element of the first bearing, the arcuate portion being used to pre-position the rolling element of the first bearing in the assembly process state.

[0008] In one embodiment, the second bearing is provided with a snap-fit ​​portion and a snap-fit ​​mating portion; the snap-fit ​​portion snaps into the snap-fit ​​mating portion so that the positioning member and the outer ring of the second bearing are connected, thereby enabling the outer ring of the second bearing to drive the positioning member to move axially.

[0009] In one embodiment, the snap-fit ​​portion comprises a plurality of protrusions disposed on the circumferential outer side of the outer ring of the second bearing; the snap-fit ​​mating portion comprises a slot adapted to the protrusions, the slot being disposed on the circumferential inner side of the positioning member; the protrusions can be inserted into the slots to tightly engage the protrusions and the slots, thereby fixing the positioning member to the outer ring of the second bearing.

[0010] In one embodiment, the support structure further includes a clamping member connected to the outer ring of the second bearing; the outer ring of the second bearing includes a connecting section extending axially, the connecting section and the clamping member being connected by a thread to generate a preload; in the assembly process state, the clamping member generates the preload by means of the threaded connection, causing the outer ring of the second bearing to move upward, thereby pushing the blade holder upward, thereby reaching the assembled position state.

[0011] In one embodiment, the support structure further includes an axial positioning member, which is assembled to the blade shank, and both ends of the axial positioning member abut against the inner ring of the first bearing and the inner ring of the second bearing, respectively, thereby providing axial positioning for the first bearing and the second bearing.

[0012] In one embodiment, the support structure further includes a bushing mounted on the axially outer side of the outer ring of the second bearing, and the bushing and the hub are in a sealing sliding fit.

[0013] Another aspect of the present invention provides a fan, including a hub, blades, and a support structure for supporting the blades on the hub; the support structure is any of the support structures described above.

[0014] Another aspect of the present invention provides a method for assembling a fan, wherein the fan is the fan described above; the assembly method includes: assembling the outer ring of a first bearing of a support structure to a hub; assembling the inner ring of the first bearing and a second bearing of the support structure to the blade shank; inserting the blade shank, on which the inner ring of the first bearing and the second bearing are assembled, into an assembly channel of the hub; pressing the blade shank downward until the annular step of the outer ring of the second bearing presses against the annular protrusion of the hub; assembling the rolling element of the first bearing to the inner ring of the first bearing; and pushing the blade shank upward, thereby pressing the rolling element of the first bearing against the outer ring and the inner ring of the first bearing.

[0015] The support structure provided by this invention is equipped with an annular step that matches the annular protrusion of the hub. By moving the blade shank, the annular step and the annular protrusion of the support structure maintain or eliminate the axial distance, thereby forming an assembled state and an assembly process state. This allows the rolling elements of the first bearing to be assembled in the assembly process state and to complete the assembly or disassembly of the rolling elements of the first bearing in the assembled state. The assembly of the rolling elements of the first bearing can be achieved without opening holes or slots in the hub. The assemblability and manufacturability of individual parts are good. Moreover, the modification to existing mature structures is small, the parts processing technology and structure are simple, and it does not affect the structural strength of the blades and hub. It can realize the rapid disassembly or assembly of blades, improve the economy of the engine, and is suitable for assembly or disassembly of blades in test sites, airports and other units. Attached Figure Description

[0016] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0017] Figure 1 This is a schematic diagram of the original support structure used to support the blades on the hub;

[0018] Figure 2 This is a schematic diagram of an embodiment of the support structure according to the present invention in the assembly process state;

[0019] Figure 3 yes Figure 2 A schematic diagram of the support structure in the assembled state;

[0020] Figure 4 yes Figure 2 Orthographic projection of the positioning components of the supporting structure in the middle;

[0021] Figure 5 yes Figure 4 The front view of the positioning component;

[0022] Figure 6 yes Figure 5 A sectional view of the positioning element along line AA;

[0023] Figure 7 This is a schematic flowchart of an embodiment of the fan assembly method according to the present invention. Detailed Implementation

[0024] The following embodiments are for Figure 1The support structure shown has been improved. The term "open rotor" refers to a turbine engine with an open rotor structure design. Compared to the high-bypass turbofan engines widely used in the current civil aviation field, open rotor engines, also known as propfan engines, have significantly increased propulsion efficiency and can greatly reduce fuel consumption due to their significantly higher bypass ratio.

[0025] The superior fuel economy of open rotary engines relies heavily on their ultra-large, wide-chord swept blades, with diameters reaching 4 meters or even larger. This unique configuration and massive size also present challenges during installation and disassembly. For instance, during packaging and transportation, blades are typically disassembled into individual pieces or components and transported with the engine block, only to be reassembled upon arrival at the destination. Therefore, the assemblability of the blade support structure is crucial. Figure 1 As shown, the fan of the open rotor engine needs to rotate around the axial direction of the blade stalk 2. Most of its blades are designed to be supported on the hub 1 by bearings to achieve the adjustment of the blade pitch angle, thereby improving the aerodynamic performance and economy of the entire route.

[0026] The blade involves many parts during assembly / disassembly. If all parts are assembled during the final assembly, and the blade is disassembled down to the part level, it will take a lot of time and inevitably make the assembly process more complex, requiring additional special tooling, which will increase the related costs for both the testing unit and the user unit.

[0027] To solve the above problems, such as Figure 1 As shown, the current solution involves providing openings 1a in the hub 1 and bearing housing for accommodating the rolling elements 11 of the first bearing 10. However, this solution compromises the integrity of the bearing outer ring structure and the hub 1 structure. The rolling elements 11 of the first bearing 10 experience significant vibration as they pass through opening 1a, which substantially affects the strength of the first bearing 10 and the hub 1. Figure 1 As shown, an additional plug 3 that is compatible with the opening 1a is required, which increases the structural complexity and cost.

[0028] Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided to explain the invention and not to limit it. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made to the invention without departing from the scope or spirit thereof. For example, a feature shown or described as part of one embodiment may be used with another embodiment to produce yet another embodiment. Therefore, the invention is intended to cover these modifications and variations that fall within the scope of the appended claims and their equivalents.

[0029] As used herein, the term "axial" refers to the central axis of the structure or a direction parallel to the central axis of the structure, and the term "circumferential" refers to the direction about the "axial". The terms "first" and "second" may be used interchangeably to distinguish one component from another and are not intended to indicate the position or importance of individual components.

[0030] It should be noted that the terms "upper," "lower," "left," "right," and other similar terms are merely positional relationships in the attached diagrams and do not represent the actual spatial positions during structural assembly.

[0031] exist Figure 1 Based on the support structure shown, Figure 2 and Figure 3 An embodiment of the support structure of the present invention is shown. The support structure of the present invention is applied to the fan of an open rotor engine. The fan includes a hub 1 and blades, each blade having a shank 2. The support structure is mounted on the shank 2, and the hub 1 provides an assembly channel in which the support structure is mounted so that the blades are supported on the hub 1. The support structure includes a first bearing 100, the inner ring 110 of which presses against the shank 2, and the outer ring 120 of which is mounted on the hub 1. The rolling elements 130 of the first bearing 100 can be assembled or disassembled between the outer ring 120 and the inner ring 110. The support structure also includes a second bearing 200, the inner ring 210 of which presses against the shank 2, and the outer ring 220 of which mates with the hub 1. An annular protrusion 1b is provided in the assembly channel of the hub 1. The outer ring 220 of the second bearing 200 provides an annular step 221 that matches the annular protrusion 1b. The support structure of the present invention includes an assembled position state and an assembled process state. In the assembled state, the annular protrusion 1b and the annular step 221 maintain an axial distance, and the rolling elements 130 of the first bearing 100 are assembled or disassembled. During the assembly process, the annular protrusion 1b presses against the annular step 221, thereby eliminating the axial distance and providing an axial assembly distance between the inner ring 110 and the outer ring 120 of the first bearing 100 for operating the rolling elements 130 of the first bearing 100. This assembly distance is equal to the axial distance.

[0032] The support structure of the present invention is provided with an annular step 221 that matches the annular protrusion 1b of the hub 1. By moving the blade shank 2, the annular step 1b and the annular protrusion 221 of the support structure maintain or eliminate the axial distance, so as to form an assembly-in state and an assembly process state. This allows the rolling elements 130 of the first bearing 100 to be assembled in the assembly process state, and to complete the assembly or disassembly of the rolling elements 130 of the first bearing 100 in the assembly-in state. The assembly of the rolling elements 130 of the first bearing 100 can be achieved without opening holes or slots in the hub 1. The assemblability and the manufacturability of individual parts are good. Moreover, the modification to the existing mature structure is small, the part processing technology and structure are simple, and it does not affect the structural strength of the blade and the hub 1. It can realize the rapid disassembly or assembly of the blade, improve the economy of the engine, and is suitable for assembly or disassembly of blades in test sites, airports and other units.

[0033] like Figure 2 As shown, the support structure is in the assembly process state. In this state, because the blade shank 2 and the entire support structure are pushed downwards until the annular step 221 of the outer ring 220 of the second bearing 200 presses against the annular protrusion 1b of the hub 1, the outer ring 220 of the second bearing 200 can no longer move downwards. At this time, the rolling element 130 of the first bearing 100 can be assembled onto the inner ring 110 of the first bearing 100 through the assembly space 400 formed by the assembly distance between the inner ring 110 and the outer ring 120 of the first bearing 100, or the assembled rolling element 130 of the first bearing 100 can be disassembled from the inner ring 110 of the first bearing 100 through the assembly space 400, so as to achieve the purpose of rapid assembly or disassembly.

[0034] like Figure 3 As shown, the support structure is in the assembled state. During the assembly process, the rolling element 130 of the first bearing 100 has been assembled onto the inner ring 110 of the first bearing 100 or has been disassembled. At this time, the blade shank 2 is pushed upward, causing the annular step 221 of the outer ring 220 of the second bearing 200 to disengage from the annular protrusion 1b of the hub 1. The inner ring 110 of the first bearing 100 moves upward to compress the assembly distance until the inner ring 110 of the first bearing 100 is compacted onto the rolling element 130, and the rolling element 130 is compacted onto the outer ring 120 of the first bearing 100. The axial distance between the annular protrusion 1b and the annular step 221 is L. At this time, the support structure is in the assembled state.

[0035] like Figure 3As shown, in the assembled state, the axial distance between the annular step 221 and the annular protrusion 1b is L. The axial distance L in the assembled state needs to be determined in conjunction with the dimensions of the hub 1 and the rolling element 130 of the first bearing 100. Determining a suitable L ensures that the assembly distance is greater than the diameter of the rolling element 130 of the first bearing 100, guaranteeing the smooth assembly or disassembly of the rolling element 130 of the first bearing 100.

[0036] As the load-bearing frame of the entire structure, the hub 1 evenly transmits centrifugal and aerodynamic loads from the blades to the engine through a force transmission structure. Therefore, the hub 1 structure is relatively robust. Furthermore, according to the support structure of the present invention, the hub 1 has no openings or slots in the force transmission path, requiring minimal modification to existing mature structures, such as the hub 1, resulting in better structural strength for the hub 1.

[0037] In one embodiment, the first bearing 100 is a cageless full complement thrust ball bearing. The second bearing 200 is a tapered roller bearing with a cage structure. Thus, the rolling elements 230 of the second bearing 200 can be held within a predetermined spacing and relative position. The second bearing 200 can be assembled or disassembled as a single unit. Both the first bearing 100 and the second bearing 200 are lubricated with low-temperature grease.

[0038] Figures 4 to 6 The structure of the positioning element 500 in the support structure is shown. In one embodiment, the support structure further includes the positioning element 500. The positioning element 500 is connected to the outer ring 220 of the second bearing 200, thereby enabling the outer ring 220 of the second bearing 200 to drive the positioning element 500 to move axially. Figure 2 and Figure 3 As shown, the axial length of the positioning member 500 is approximately half the length of the cage of the second bearing 200. The positioning member 500 has an arcuate portion 510 that is adapted to the rolling element 130 of the first bearing 100, and the arcuate portion 510 is used to pre-position the rolling element 130 of the first bearing 100 in the assembly process state.

[0039] refer to Figure 4 The positioning element 500 is annular, and multiple arcuate portions 510 are provided on its circumferential ends. The number of arcuate portions 510 matches the number of rolling elements 130 of the first bearing 100. The multiple arcuate portions 510 are evenly distributed on the positioning element 500. The material of the positioning element 500 can be engineering plastic with low hardness, so that if the positioning element 500 collides with the rolling elements 130 of the first bearing 100, the positioning element 500 will not cause wear to the rolling elements 130.

[0040] Furthermore, combined Figure 2 and Figure 3The outer circumferential side of the outer ring 220 of the second bearing 200 is provided with a snap-fit ​​portion 222, and the inner circumferential side of the positioning member 500 is provided with a snap-fit ​​mating portion 520. The snap-fit ​​portion 222 snaps into the snap-fit ​​mating portion 520, so that the positioning member 500 and the outer ring 220 of the second bearing 200 are connected. Figure 2 and Figure 3 As shown, the outer ring 220 of the second bearing 200 extends downward and has a relatively long axial length. It is connected to the positioning member 500 through the snap-fit ​​part 222, which can drive the positioning member 500 to move axially.

[0041] In one embodiment, the snap-fit ​​portion 222 comprises multiple protrusions (hereinafter referred to as protrusions by reference numeral 222), which are disposed on the circumferential outer side of the outer ring 220 of the second bearing 200. The snap-fit ​​mating portion 520 is a slotted portion (hereinafter referred to as a slotted portion) adapted to the protrusions 222. The slotted portion 520 is disposed on the circumferential inner side of the positioning member 500. The protrusions 222 can be inserted into the slotted portion 520 so that the protrusions 222 and the slotted portion 520 are tightly engaged, thereby fixing the positioning member 500 to the outer ring 220 of the second bearing 200. Figure 4 As shown, in one specific embodiment, the slotted portion 520 is a through opening. The number of protrusions 222 and slotted portions 520 is the same. The slotted portions 520 are symmetrically arranged in the circumferential direction of the positioning member 500 to ensure the connection stability of the positioning member 500 and the outer ring 220 of the second bearing 200.

[0042] In another embodiment, the snap-fit ​​portion 222 is a plurality of slotted portions, and the snap-fit ​​mating portion 520 is a plurality of protrusions, which can also realize the connection between the positioning member 500 and the outer ring 220 of the second bearing 200, which will not be described in detail here.

[0043] In one embodiment, the support structure further includes a dust cover 910. The dust cover 910 is a single thin plate covering the outside of the bearing cavity for sealing and dust prevention. The dust cover 910 can be made of aluminum alloy, which is lightweight and helps to reduce the overall weight of the structure.

[0044] In one embodiment, the support structure further includes an air intake shroud 920. The air intake shroud 920 forms the outer flow channel surface of the entire fan. The air intake shroud 920 has radial openings, allowing the blade shanks 2 to be inserted radially into the hub 1.

[0045] In one embodiment, the support structure further includes an axial spacer 600, which is assembled on the blade shank 2. The two ends of the axial positioning member 500 abut against the inner ring 110 of the first bearing 100 and the inner ring 210 of the second bearing 200, respectively, thereby providing axial positioning for the first bearing 100 and the second bearing 200.

[0046] The inner ring 110 of the first bearing 100, the axial spacer 600, and the inner ring 210 of the second bearing 200 are all circumferentially split structures, and the inner rings are all interference-fitted. Because there is a radial clearance between the second bearing 200 and the axial spacer 600, the low-temperature grease filling the two bearings (i.e., the first bearing 100 and the second bearing 200) can flow along this clearance. To ensure lubrication, the grease needs to fill the entire bearing cavity space (including the aforementioned radial clearance). The grease replenishment interval is determined based on the load conditions and can be determined by measuring the grease condition: after the initial test, a grease sample should be taken and its dropping point, cone penetration, pressure oil separation, and acid value measured to ensure they all meet design requirements. Multiple measurements should be taken to determine the grease replenishment interval. When replenishing grease, first loosen the fixing bolts of the dust cover 910, move the dust cover 910, and use a tool to inject grease into the first bearing 100. The grease can flow into the second bearing 200 along the radial clearance.

[0047] In one embodiment, the support structure further includes a clamping member 700. The clamping member 700 is connected to the outer ring 220 of the second bearing 200. The clamping member 700 is a fastener for the entire support structure, and the first bearing 100 and the second bearing 200 can be pre-tightened through the clamping member 700. The clamping member 700 may be a clamping nut.

[0048] In one embodiment, the outer ring 220 of the second bearing 200 includes an axially extending connecting section 223, which is threadedly connected to the clamping member 700 to generate a preload. The outer ring of the connecting section 223 is threaded, preferably using aerospace threads, with a large radius root radius arc at the root of the thread to improve strength. Correspondingly, the inner circumferential side of the clamping member 700 is also threaded, and both have the same thread specification.

[0049] like Figure 2 and Figure 3 As shown, the axial distance maintained by the annular protrusion 1b and the annular step 221 in the assembled state results in the thread length ratio of the connecting section 223 of the outer ring 220 of the second bearing 200 being greater than that of the thread length of the clamping member 700.

[0050] During the assembly process, such as Figure 2 As shown, the clamping member 700 generates a preload force through a threaded connection that causes the outer ring 220 of the second bearing 200 to move upward, thereby pushing the blade shank 2 upward to reach the assembled position.

[0051] Considering the large tightening torque of the clamping component 700, a countersunk hole (not shown) is provided on the end face where the hub 1 and the clamping component 700 contact. A wear-resistant pad is provided in the countersunk hole, and the clamping component 700 is pressed onto the hub 1 through the wear-resistant pad to avoid wear on the hub 1 and the clamping component 700, thereby protecting the hub 1.

[0052] Before inserting the blade shank 2 into the assembly channel of the hub 1, the clamping member 700 can be pre-assembled onto the upper end of the connecting section 223 of the outer ring 220 of the second bearing 200. Since the clamping member 700 and the upper end of the connecting section 223 of the outer ring 220 of the second bearing 200 are only engaged by a few threads at this time, the blade shank 2 can move downwards in the assembly channel until the axial distance L is eliminated, and finally the assembly process is achieved.

[0053] After the rolling element 130 of the first bearing 100 is assembled into the inner ring 110 of the first bearing 100, the clamping member 700 is tightened. At this time, the preload generated by the clamping member 700 pulls the outer ring 220 of the second bearing 200 upward until the axial distance L is restored to the distance in the assembled state, so as to achieve the assembled state.

[0054] In one embodiment, the support structure further includes a bushing 800, which is mounted axially outside the outer ring 220 of the second bearing 200, and the bushing 800 and the hub 1 are in a sealing sliding fit. The inner and outer cylindrical surfaces of the bushing 800 are respectively interference-fitted with the outer surfaces of the hub 1 and the outer ring 220 of the second bearing 200, which can achieve the sealing function without affecting its axial sliding within the hub 1. The bushing 800 is cut at one point in the circumferential direction, but not in half, and can be pried open from the cut notch for assembly. Figure 2 and Figure 3 As shown, the outer side of the outer ring 220 of the second bearing 200 is provided with a groove to match the boss of the bushing 800. The boss of the bushing 800 is fixed by being embedded in the groove of the outer ring 220 of the second bearing 200. The bushing 800 can be made of engineering plastic.

[0055] Figure 7 A fan assembly method according to the present invention is shown, including steps S100 to S600:

[0056] In step S100, the outer ring 120 of the first bearing 100 of the support structure is assembled onto the hub 1.

[0057] In step S200, the inner ring 110 of the first bearing 100 and the second bearing 200 of the support structure are assembled to the blade shank 2.

[0058] In step S300, the inner ring 110 of the first bearing 100 and the blade 2 of the second bearing 200 are inserted into the assembly channel of the hub 1.

[0059] In step S400, the blade shank 2 is pressed down until the annular step 221 of the outer ring 220 of the second bearing 200 presses against the annular protrusion 1b of the hub 1.

[0060] In step S500, the rolling element 130 of the first bearing 100 is assembled onto the inner ring 110 of the first bearing 100.

[0061] In step S600, the blade shank 2 is pushed upward, thereby pressing the rolling element 130 of the first bearing 100 against the outer ring 120 and the inner ring of the first bearing 100.

[0062] In one embodiment, in step S100, the outer ring 120 of the first bearing 100 of the support structure is assembled to the hub 1, and the dust cover 910 is not assembled for the time being.

[0063] In one embodiment, in step S200, a second bearing 200, a bushing 800, an axial spacer 600, a positioning member 500, and the inner ring 110 of the first bearing 100 are pre-assembled on the blade holder 2. During assembly, all the above parts are placed in a horizontal position, and the tooling overcomes their weight and keeps the rolling elements 130 of the first bearing 100 locked in the arcuate portion 510 of the positioning member 500 to prevent them from falling off. The hub 1 remains stationary as the assembly reference for the blade.

[0064] In one embodiment, in step S300, the blade 2 passes through the opening of the air intake shroud 920 along the axial direction and is inserted into the hub 1.

[0065] In one embodiment, in step S400, since the clamping member 700 and the outer ring 220 of the second bearing 200 are only engaged by a few threads, the blade shank 2 can move downwards continuously, passing the position where the outer ring 220 of the second bearing 200 was in the assembled state, and then moving an axial distance L until the outer ring 220 of the second bearing 200 presses against the annular protrusion 1b of the hub 1. At this point, the blade shank 2 can no longer move downwards, reaching the assembly process state, and the axial distance L has been eliminated. In the above-described assembly process state, the positioning member 500 is close to the inner ring surface of the hub 1, making it relatively convenient to load the rolling elements 130 (i.e., steel balls) of the first bearing 100 through the tooling.

[0066] In one embodiment, in step S500, the rolling element 130 of the first bearing 100 is first inserted into the arc portion 510 of the positioning member 500 for positioning, thereby achieving the positioning of the rolling element 130 on the inner ring 110 of the first bearing 100.

[0067] In one embodiment, in step S600, after all the rolling elements 130 are filled, the clamping member 700 is tightened. At this time, the preload will pull the second bearing 200, and then push the bushing 800, axial spacer 600, positioning member 500, and the inner ring 110 and rolling elements 130 of the first bearing 100 pre-assembled thereon through the blade 2, until the inner ring 110 of the first bearing 100 is compacted onto the rolling elements 130, and the rolling elements 130 are compacted onto their outer ring. Figure 3 As shown, the support structure is now in the assembled position.

[0068] In one embodiment, after step S600, the fan assembly method further includes step S700. In step S700, the dust cover 910 is assembled onto the hub 1.

[0069] In step S700, during the movement of the blade stalk 2, before it reaches the position of the assembly process, grease should be added to the first bearing 100. After the grease is added, the dust cover 910 is assembled, the connecting bolts of the dust cover 910 are tightened, and the dust cover 910 is fixed to the hub 1.

[0070] The fan of the present invention includes a hub 1, blades, and a support structure for supporting the blades on the hub 1. The support structure is the support structure described above.

[0071] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A support structure for a fan of an open rotor engine, the fan including a hub and blades, the blades having shanks, the support structure being fitted to the shanks, the hub providing a mounting channel, the support structure being fitted within the mounting channel such that the blades are supported on the hub; The support structure includes a first bearing, the inner ring of the first bearing pressing against the blade shank, the outer ring of the first bearing being assembled to the hub, and the rolling elements of the first bearing being assembled between the outer ring and the inner ring. The support structure also includes a second bearing, the inner ring of which presses against the blade shank, and the outer ring of which mates with the hub. Its features are, An annular protrusion is provided in the assembly channel of the wheel hub; The outer ring of the second bearing is provided with an annular step that matches the annular protrusion; When assembled, the annular protrusion and the annular step maintain an axial distance in the axial direction; During assembly, the annular protrusion presses against the annular step, thereby eliminating the axial distance and ensuring that the inner and outer rings of the first bearing provide an axial assembly distance for operating the rolling elements of the first bearing; wherein, The assembly distance is equal to the axial distance.

2. The support structure as described in claim 1, characterized in that, The support structure further includes a positioning element, which is connected to the outer ring of the second bearing; The positioning element has an arcuate portion that is adapted to the rolling element of the first bearing, the arcuate portion being used to pre-position the rolling element of the first bearing in the assembly process state.

3. The support structure as described in claim 2, characterized in that, The second bearing is provided with a snap-fit ​​part, and the first bearing is provided with a snap-fit ​​mating part; The snap-fit ​​part snaps into the snap-fit ​​mating part so that the positioning member and the outer ring of the second bearing are connected, thereby enabling the outer ring of the second bearing to drive the positioning member to move axially.

4. The support structure as described in claim 3, characterized in that, The snap-fit ​​portion comprises multiple protrusions, which are disposed on the circumferential outer side of the outer ring of the second bearing; The snap-fit ​​part is a slotted part that matches the protrusion part, and the slotted part is located on the circumferential inner side of the positioning member; The protrusion can be inserted into the slot so that the protrusion and the slot can be tightly engaged, thereby fixing the positioning member to the outer ring of the second bearing.

5. The support structure as described in any one of claims 1 to 4, characterized in that, The support structure also includes a clamping member connected to the outer ring of the second bearing; The outer ring of the second bearing includes an axially extending connecting section, and the connecting section and the clamping member are connected by a thread to generate a preload. During the assembly process, the clamping member generates a preload force by means of the threaded connection, which moves the outer ring of the second bearing upward, thereby pushing the blade holder upward to reach the assembled position.

6. The support structure as described in any one of claims 1 to 4, characterized in that, The support structure further includes an axial spacer, which is assembled to the blade shank, and both ends of the axial spacer abut against the inner ring of the first bearing and the inner ring of the second bearing, respectively, thereby providing axial positioning for the first bearing and the second bearing.

7. The support structure as described in any one of claims 1 to 4, characterized in that, The support structure further includes a bushing, which is installed on the axially outer side of the outer ring of the second bearing, and the bushing and the hub are in a sealing sliding fit.

8. A fan, comprising a hub, blades, and a support structure for supporting the blades on the hub; Its features are, The support structure is the support structure described in any one of claims 1-7.

9. A method for assembling a fan, characterized in that, The fan is the fan according to claim 8; The assembly method includes: The outer ring of the first bearing of the support structure is assembled onto the wheel hub; The inner ring of the first bearing and the second bearing of the support structure are assembled to the blade shank. Insert the inner ring, which is fitted with the first bearing, and the blade shank, which is fitted with the second bearing, into the assembly channel of the hub; Press the blade shank downwards until the annular step of the outer ring of the second bearing presses against the annular protrusion of the hub; The rolling elements of the first bearing are assembled into the inner ring of the first bearing; The blade holder is pushed upward, thereby pressing the rolling element of the first bearing against the outer ring and the inner ring of the first bearing.

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