Unpowered automatic feathering mechanism of variable pitch mechanism of aerial variable pitch propeller and propeller
The aerial variable pitch propeller variable pitch mechanism uses aerodynamic power to achieve automatic feathering without power, which solves the energy loss problem when the aircraft's power motor fails, and improves the safety and landing possibility of the aircraft.
Patent Information
- Application Number
- CN202422782556.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2025-08-26
- Estimated Expiration
- 2034-11-15
AI Technical Summary
In the prior art, the aircraft cannot automatically complete the feathering when the power motor fails, resulting in a loss of propeller energy, reducing gliding time and safety.
The aerial variable pitch propeller variable pitch mechanism is adopted to drive the variable pitch disc without power automatically, and the combination of variable pitch lead screw, variable pitch nut and flexible material is designed to achieve powerless rapid feathering.
After the power motor fails, it can quickly reduce the fuselage resistance and increase the possibility of safe landing of the aircraft. It has fast response speed and high safety, and does not rely on hydraulic or spring power.
Smart Images
Figure CN223267036U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of propellers, in particular to an unpowered automatic feathering mechanism of an aerial variable pitch propeller and a propeller. Background Art
[0002] Feathering refers to adjusting the propeller blade angle to be almost parallel to the aircraft's flight direction, minimizing the propeller's resistance in the air.
[0003] If an engine or motor fails during cruising, the propellers will be locked and stopped by locking the power source. Propeller feathering reduces wind resistance and prevents the high-speed propellers from dragging the faulty engine. This reduces drag, improves glide performance, and increases the likelihood of a safe landing. Feathered propellers reduce aerodynamic interference with the aircraft, making it easier for the aircraft to maintain a stable flight attitude.
[0004] Traditionally, feathering is achieved for variable-pitch propellers in mid-flight, typically through a hydraulic, electric, or mechanical system. When the pilot triggers a feathering command, the system automatically adjusts the propeller blades to the feathered position.
[0005] like Figure 1 As shown in the figure, the pitch mechanism of the variable pitch propeller driven by the motor in the air is composed of a pitch screw, a pitch nut, a pitch disc, and a pitch nut; the pitch hub clamps the pitch screw axially for positioning, and the motor drives the pitch screw to rotate in both directions at a uniform speed. The rotation of the pitch screw drives the pitch nut axially, thereby causing the pitch disc to move axially, the pitch disc slot to move axially, and the pitch pin of the propeller handle to move in a circular motion to achieve blade pitch change, as shown in the figure. Figure 2 As shown, the pitch disc is driven from the upper limit to the lower limit, and the movement time is relatively long, which places extremely high requirements on the speed of the pitch motor.
[0006] like Figure 3 As shown, the difference between hydraulic and electric pitch change is that the pitch disc is driven by hydraulic oil pressure and a pitch spring. The engine's hydraulic oil pump provides pressure. When the oil pressure exceeds the spring thrust, the pitch disc, integrated with the piston, moves upward, driving the pitch pin in the propeller handle to rotate in a circular motion, reducing the pitch angle to the corresponding operating angle. When the hydraulic pressure decreases below the pitch spring thrust, the spring pushes the pitch disc downward, increasing the pitch angle. When the oil pressure completely disappears, the spring thrust reaches the lower limit, achieving the propeller feathering position. The safety of hydraulic pitch change depends primarily on the fatigue performance of the spring, which plays a decisive role.
[0007] Both existing technologies require the pilot to actively trigger the propeller feathering command. When the propeller loses power, the propeller feathering cannot be completed automatically, causing the propeller to lose some energy and reducing the gliding time. Utility Model Content
[0008] In view of the above-mentioned defects in the prior art, the purpose of the present invention is to provide an air-variable pitch propeller pitch-changing mechanism with an unpowered automatic feathering mechanism and a propeller.
[0009] In order to achieve the above purpose, the present invention adopts the following technical solutions:
[0010] On the one hand, the utility model provides an unpowered automatic pitch feathering mechanism for an aerial variable pitch propeller pitch changing mechanism, comprising a pitch disc, a side wall of the pitch disc being provided with a slide groove, the slide groove being slidably connected to a pitch pin of a blade handle, a through hole being provided in the center of the pitch disc, a pitch nut being provided in the through hole of the pitch disc, the pitch nut being internally threadedly connected to a pitch screw, a lower limit piece being provided at the lower end of the pitch screw, and an upper limit piece being provided at the upper end of the pitch screw; the pitch disc being slidably connected to the pitch nut, and a limit seat being provided on the outer wall of the pitch nut above the pitch disc; the pitch pin of the blade handle being eccentrically connected to the blade handle, and the blade handle axis and the aerodynamic center of the blade being non-coaxial.
[0011] Furthermore, the space between the upper limit member and the lower limit member is a movement range of the pitch nut, and this range is defined as a range of variation of the working pitch angle;
[0012] The range between the limit seat of the pitch nut and the lower limit piece is the movement range of the pitch disc, and the lower limit piece is the feathering position. This range is defined as the working point and the feathering position variation range.
[0013] Furthermore, a flexible material is provided between the limit seat and the pitch disc.
[0014] Furthermore, the upper limit member and the lower limit member are both composite bearings, and the composite bearing includes a large diameter portion and a small diameter portion, and the outer diameter of the large diameter portion is larger than the outer diameter of the variable pitch screw;
[0015] Specifically, the upper limit member is rotatably connected to the upper end of the variable pitch screw; the lower limit member is rotatably connected to the lower end of the variable pitch screw.
[0016] Furthermore, a guide frame is provided at the upper end of the pitch variable nut, the guide frame is provided with a first guide hole axially extending therethrough, and the pitch variable disc is provided with a second guide hole axially extending therethrough, the first guide hole and the second guide hole corresponding to each other, and at least two of each are provided;
[0017] Specifically, a first sliding guide is provided in the first guide hole, and a second sliding guide is provided in the second guide hole.
[0018] Specifically, guide posts are slidably arranged in the corresponding first sliding guide members and second sliding guide members.
[0019] Furthermore, the first sliding guide and the second sliding guide are copper sleeves or linear bearings.
[0020] Furthermore, the number of the first guide holes and the second guide holes is the same as that of the slide grooves;
[0021] Specifically, the second guide holes are evenly distributed along the circumference of the pitch disc;
[0022] Specifically, the second guide hole is located at the maximum outer diameter d of the pitch disc. max and 1 / 2 the maximum outer diameter d max between.
[0023] Furthermore, a third sliding guide is fixedly provided in the central through hole of the pitch change disc, and the third sliding guide is slidably connected to the pitch change nut;
[0024] Specifically, the flexible material is a return spring, a hollow rubber tube, or a nylon pad.
[0025] Furthermore, the third sliding guide member is a steel guide sleeve, and the steel guide sleeve is embedded in the inner wall of the through hole of the pitch disc;
[0026] Specifically, the steel guide sleeve is provided with an inner ring, the flexible material is a return spring, and the return spring extends into the steel guide sleeve and sits on the inner ring.
[0027] On the second aspect, the utility model provides an aerial variable-pitch propeller, including an upper propeller hoop and a lower propeller hoop, and is characterized in that it also includes the unpowered automatic propeller mechanism described in the first aspect; the upper limit member is fixedly connected to the upper propeller hoop, and the upper end of the guide column is fixedly connected to the upper propeller hoop; the lower limit member is fixedly connected to the lower propeller hoop, and the lower end of the guide column is fixedly connected to the lower propeller hoop; the upper propeller hoop and the lower propeller hoop rotatably clamp the propeller handle.
[0028] Compared with the prior art, the present invention has the following beneficial effects:
[0029] 1. After the power motor fails, the utility model can quickly feather the propellers without power, reducing the fuselage resistance and increasing the possibility of safe landing of the aircraft.
[0030] 2. Compared with the traditional feathering function, the present invention uses aerodynamic force as the power source and the pitch disc as the slave. The traditional feathering function can only rely on the rotation of the pitch motor as the power source to drive the blade rotation. The present invention has a high safety factor and a fast response speed. The feathering function does not rely on hydraulic power, springs or pitch motors. The change rate depends on the propeller speed and the incoming flow speed. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Figure 1 It is a schematic diagram of the structure of the pitch-changing mechanism of a conventional electric air-variable pitch propeller;
[0032] Figure 2 This is a schematic diagram of the pitch change pin's circular motion driven by the axial displacement of the pitch change disc;
[0033] Figure 3 It is a schematic diagram of the structure of the pitch-changing mechanism of a conventional hydraulic variable-pitch propeller in the air;
[0034] Figure 4 This is a structural diagram of the unpowered automatic feathering mechanism of the variable pitch propeller in the air of the utility model;
[0035] Figure 5 It is a structural diagram of the blade in the utility model.
[0036] In the figure: 1. upper limit member; 2. pitch-changing screw; 3. guide frame; 4. guide column; 5. first sliding guide; 6. second sliding guide; 7. pitch-changing plate; 8. return spring; 9. third sliding guide; 10. lower limit member; 11. pitch-changing nut. DETAILED DESCRIPTION
[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0038] Example 1:
[0039] See also Figures 4 and 5 The present invention provides an air-variable-pitch propeller pitch-changing mechanism without power automatic feathering mechanism, including a pitch disc 7, a side wall of the pitch disc 7 is provided with a slide groove for slidingly connecting the pitch pin of the blade handle, a through hole is provided in the center of the pitch disc 7, a pitch nut 11 is provided in the through hole of the pitch disc 7, the pitch nut 11 is internally threaded and connected to the pitch screw 2, the lower end of the pitch screw 2 is provided with a lower limit piece 10, and the upper end of the pitch screw 2 is provided with an upper limit piece 1. The pitch disc 7 is slidably connected with the pitch nut 11, and the outer wall of the pitch nut 11 is provided with a limited seat above the pitch disc 7. The pitch pin of the blade handle is eccentrically connected to the blade handle, and the blade handle axis is not coaxial with the aerodynamic center of the blade. There is a distance between the aerodynamic center of the blade and the blade handle axis, so that when the propeller rotates in the working state, the air generates a force arm relative to the blade handle axis at the aerodynamic center, hereinafter referred to as aerodynamic force.
[0040] The sliding connection between pitch disc 7 and pitch nut 11 is due to the fact that the aerodynamic center of the blade is not coaxial with the propeller shaft. The nose-down torque generated by the propeller rotation causes the blade to rotate about the propeller shaft, thereby causing the pitch pin to drive pitch disc 7 toward the stop seat of pitch nut 11. During the entire working state, the pitch disc is always in close contact with the stop seat of pitch nut 11. Changing the pitch angle requires rotating the pitch screw 2, which drives the pitch nut 1 up and down, thereby changing the position of pitch disc 7.
[0041] When the power motor fails, the aircraft has a forward flight speed, and the incoming airflow generates aerodynamic force on the blades, which acts on the blades to generate a lifting torque. As a power source, it drives the pitch disc 7 to move downward to realize the feathering function. The advantage of this patent is that it can quickly feather the blades without power, and the change rate depends on the propeller speed and the incoming flow speed.
[0042] Compared with the traditional feathering function, the pneumatic force of this patent is the power source and the pitch disc 7 is the driven one. The traditional feathering function can only rely on the rotation of the pitch motor as the power source to drive the blades to rotate. The patent has a high safety factor and a fast response speed. The feathering function does not rely on hydraulic power, springs or pitch motors.
[0043] Specifically, the sliding groove is slidably connected to the blade handle pitch change pin through a nylon or copper slider.
[0044] Specifically, the space between the upper limit member 1 and the lower limit member 10 is a movement range of the pitch nut 11 , and this range is defined as a range of variation of the working pitch angle.
[0045] Specifically, the range between the limit seat of the pitch nut 11 and the lower limit member 10 is the movement range of the pitch disc 7, and the lower limit member 10 is in the feathering position. This range is defined as the working point and the feathering position variation range.
[0046] Furthermore, a flexible material is provided between the limiting seat and the pitch disc 7 .
[0047] During the powered flight phase, aerodynamic forces drive the blades to rotate around the handle, generating a nose-down torque, thereby driving the pitch disc 7 upward, causing the pitch disc 7 to softly adhere to the limit seat. Flexible materials are provided to prevent excessive speed or uncontrollable impact loads during the upward movement process. The pitch screw 2 rotates to drive the pitch nut 11 to move within the pitch nut movement range, changing the upper and lower positions of the pitch disc and determining the propeller operating angle.
[0048] When the aircraft is in forward flight / cruise mode, the power motor stops rotating due to a fault, and the incoming air blows and acts on the aerodynamic center, causing the blades to generate a lifting torque. The pitch disc 7 is driven downward by the propeller handle and becomes a feathering propeller. At this time, the flexible material is in a relaxed state.
[0049] That is, in the powered flight state, the pitch disc 7 is driven upwards by the nose-up torque to move to the working position; in the unpowered flight state, the flexible material and the nose-down torque return the pitch disc 7 to the feathering position.
[0050] Preferably, the flexible material is a return spring 8 or a hollow rubber tube or a nylon pad, which plays a role of buffering and returning.
[0051] Specifically, the upper limit member 1 and the lower limit member 10 are both composite bearings, and the composite bearing includes a large diameter part and a small diameter part. The outer diameter of the large diameter part is larger than the outer diameter of the variable pitch screw 2. The upper limit member 1 is rotatably connected to the upper end of the variable pitch screw 2 and is positioned by a step; the lower limit member 10 is rotatably connected to the lower end of the variable pitch screw 2 and is positioned by a step.
[0052] Example 2:
[0053] Based on Example 1, in this embodiment, a guide frame 3 is provided at the upper end of the pitch variable nut 11, and the guide frame 3 is provided with a first guide hole axially extending therethrough, and the pitch variable disc 7 is provided with a second guide hole axially extending therethrough, and the first guide hole corresponds to the second guide hole, and at least two of each are provided; a first sliding guide member 5 is provided in the first guide hole, and a second sliding guide member 6 is provided in the second guide hole, and guide columns 4 are slidably provided in the corresponding first sliding guide members 5 and second sliding guide members 6.
[0054] Preferably, the first sliding guide 5 and the second sliding guide 6 are copper sleeves or linear bearings.
[0055] Specifically, the guide column 4 enables the pitch disc 7 and the pitch nut 11 to move only in the axial direction after being loaded, without radial and rotational forces, thereby improving the horizontality of the pitch disc 7 and the pitch nut 11.
[0056] Specifically, the number of the first guide holes and the second guide holes is the same as that of the slide groove, that is, a three-blade propeller requires three guide pillars 4, a four-blade propeller requires four guide pillars 4, and so on. The relationship between the number of blades and the number of guide pillars is arranged in a similar manner; the second guide holes are evenly distributed along the circumference of the pitch disc 7.
[0057] Specifically, the second guide hole is located at the maximum outer diameter d of the pitch disc 7. max and 1 / 2 the maximum outer diameter d max When the pitch disc 7 meets the structural strength standard, the closer the second guide hole is to the maximum outer diameter d max , the pitch disc 1 has the highest motion flatness and the best pitch change accuracy.
[0058] Specifically, the diameter of the guide column 4 needs to be calculated according to the torque applied to the pitch disc 7 by the propeller aerodynamic load, and must meet the requirement that the bending deformation of the guide column 4 does not exceed 0.1 mm under double load.
[0059] The central through hole of the pitch disc 7 is fixedly provided with a third sliding guide 9, and the third sliding guide 9 is slidingly connected to the pitch nut 11. The third sliding guide 9 is a steel guide sleeve, and the steel guide sleeve is provided with an inner ring. The flexible material is a return spring 8, and the return spring 8 extends into the steel guide sleeve and sits on the inner ring.
[0060] Specifically, the compression amount and compression force of the return spring 8 are determined by the conversion of aerodynamic torque generated at a certain rotation speed into axial force, but are not limited to these conditions.
[0061] Specifically, the steel guide sleeve is embedded in the inner wall of the through hole of the pitch disc 7 , and the steel guide sleeve serves as a sliding guide and prevents the return spring 8 from wearing the pitch disc 7 .
[0062] Example 3:
[0063] On the basis of Example 2, when the unpowered automatic propeller feathering mechanism of the pitch changing mechanism of the air-variable pitch propeller is applied to the propeller, the upper limit member 1 is fixedly connected to the upper propeller hoop, the upper end of the guide column 4 is fixedly connected to the upper propeller hoop, the lower limit member 10 is fixedly connected to the lower propeller hoop, the lower end of the guide column 4 is fixedly connected to the lower propeller hoop, and the upper propeller hoop and the lower propeller hoop rotate to clamp the propeller handle.
[0064] All components not discussed in detail in this application and the connection methods of the components in this application are well-known technologies in the technical field and can be directly applied without further explanation.
[0065] In this utility model, the term "plurality" refers to two or more, unless otherwise specified. Terms such as "installed," "connected," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean fixed, removable, or integral; "connected" can mean directly or indirectly through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this utility model based on specific circumstances.
[0066] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "front" and "back" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the present invention.
[0067] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.
Claims
1. An unpowered automatic feathering mechanism for an aerial variable-pitch propeller pitch change mechanism, comprising a pitch disc, a sidewall of which is provided with a slide groove, said slide groove being slidably connected to a pitch pin on a propeller handle, a through hole provided at the center of the pitch disc, a pitch nut provided in the through hole of the pitch disc, said pitch nut being internally threadedly connected to a pitch screw, a lower limit member provided at the lower end of the pitch screw, and an upper limit member provided at the upper end of the pitch screw; It is characterized by: The pitch disc is slidably connected to the pitch nut, and a limited position seat is provided on the outer wall of the pitch nut above the pitch disc; The propeller shaft pitch-changing pin is eccentrically connected to the propeller shaft of the blade, and the propeller shaft axis and the aerodynamic center of the blade are not coaxial.
2. The unpowered automatic feathering mechanism of the variable pitch propeller pitch changing mechanism in the air according to claim 1, characterized in that: The range between the upper limit member and the lower limit member is the movement range of the pitch nut, and this range is defined as the range of variation of the working pitch angle; The range between the limit seat of the pitch nut and the lower limit piece is the movement range of the pitch disc, and the lower limit piece is the feathering position. This range is defined as the working point and the feathering position variation range.
3. The unpowered automatic feathering mechanism of the variable pitch propeller pitch changing mechanism in the air according to claim 1, characterized in that: A flexible material is provided between the limiting seat and the pitch disc.
4. The unpowered automatic feathering mechanism of the variable pitch propeller pitch changing mechanism in the air according to claim 1, characterized in that: The upper limit member and the lower limit member are both composite bearings, and the composite bearing includes a large diameter portion and a small diameter portion, and the outer diameter of the large diameter portion is larger than the outer diameter of the variable pitch screw; The upper limit member is rotatably connected to the upper end of the variable pitch lead screw; the lower limit member is rotatably connected to the lower end of the variable pitch lead screw.
5. The unpowered automatic feathering mechanism of the variable pitch propeller pitch changing mechanism in the air according to claim 1, characterized in that: A guide frame is provided at the upper end of the pitch-changing nut, and the guide frame is provided with a first guide hole extending axially therethrough. The pitch-changing disc is provided with a second guide hole extending axially therethrough. The first guide hole corresponds to the second guide hole, and at least two of each are provided. A first sliding guide is provided in the first guide hole, and a second sliding guide is provided in the second guide hole. Guide posts are slidably arranged in the corresponding first sliding guide member and the second sliding guide member.
6. The unpowered automatic feathering mechanism of the variable pitch propeller pitch changing mechanism in the air according to claim 5, characterized in that: The first sliding guide and the second sliding guide are copper sleeves or linear bearings.
7. The unpowered automatic feathering mechanism of the variable pitch propeller pitch changing mechanism in the air according to claim 5, characterized in that: The number of the first guide holes and the second guide holes is the same as that of the slide grooves; The second guide holes are evenly distributed along the circumference of the pitch disc; The second guide hole is located at the maximum outer diameter d of the pitch disc. max and 1 / 2 the maximum outer diameter d max between.
8. The unpowered automatic feathering mechanism of the variable pitch propeller pitch changing mechanism in the air according to claim 3, characterized in that: A third sliding guide is fixedly provided in the central through hole of the pitch change disc, and the third sliding guide is slidably connected to the pitch change nut; The flexible material is a return spring, a hollow rubber tube or a nylon pad.
9. The unpowered automatic feathering mechanism of the variable pitch propeller pitch changing mechanism in the air according to claim 8, characterized in that: The third sliding guide member is a steel guide sleeve, and the steel guide sleeve is embedded in the inner wall of the through hole of the pitch disc; The steel guide sleeve is provided with an inner ring, and the flexible material is a return spring, which extends into the steel guide sleeve and sits on the inner ring.
10. An aerial variable pitch propeller, comprising an upper propeller hoop and a lower propeller hoop, characterized in that: Also includes the unpowered automatic feathering mechanism of claim 5; The upper limit member is fixedly connected to the upper paddle hoop, and the upper end of the guide column is fixedly connected to the upper paddle hoop; the lower limit member is fixedly connected to the lower paddle hoop, and the lower end of the guide column is fixedly connected to the lower paddle hoop; the upper paddle hoop and the lower paddle hoop rotatably clamp the paddle handle.