Shimmy offset variable-total-pitch propeller hub structure

Abstract

The invention belongs to the technical field of electric propulsion system propeller hub design, and particularly relates to a shimmy offset variable total pitch propeller hub structure. Comprising an upper propeller shell, a lower propeller shell, a supporting arm and a control assembly, a first flange set axially presses the upper propeller shell and the lower propeller shell, and the first flange set is in small clearance fit with the upper propeller shell and the lower propeller shell to transmit torque; the control assembly penetrates through the middle of the upper propeller shell and the lower propeller shell, a plurality of transverse grooves distributed in the circumferential direction are formed in the middle section of the control assembly, the supporting arm comprises a variable-pitch rocker arm, one end of the variable-pitch rocker arm is connected with the end of the propeller blade metal piece through a bolt, and the other end of the variable-pitch rocker arm is in clearance fit with the transverse grooves of the control assembly; the control assembly rotates together with the upper propeller shell and the lower propeller shell, and can slide up and down along the upper propeller shell and the lower propeller shell to drive all the variable-pitch rocker arms to do circular motion around the axes of the corresponding support arms, so that the variable-pitch motion of the total pitch of the support arms is realized, and a certain distance exists between the axis of each support arm and the axis of the rotor wing; and the lower paddle shell is connected with the motor through a second flange group and a motor pin.

Description

Technical Field

[0001] The invention belongs to the technical field of propeller hub design for electric propulsion systems, and in particular relates to a propeller hub structure with a swing-biased variable collective pitch. Background Art

[0002] The traditional hingeless propeller hub is connected to the main reducer drive shaft through a spline, and the axial hinge is an elastic bearing or bearing group structure. The total pitch and cyclic pitch movement are achieved through the external control of the automatic tilt device. When the space layout and weight requirements are high, the traditional propeller hub configuration has the disadvantages of complex structure, large size, large overall weight, and insufficient bearing capacity. The axis of the traditional propeller hub arm passes through the center of the rotor. When the control load is large, the traditional propeller hub configuration has the disadvantages of insufficient component strength or excessive weight. Summary of the invention

[0003] Purpose of the invention: To provide a hub structure with a simple structure and a variable collective pitch with a swing offset.

[0004] Technical solution:

[0005] A swing-biased variable collective pitch propeller hub structure comprises: an upper propeller shell 1, a lower propeller shell 2, a support arm 3, and a control assembly 5, wherein the upper propeller shell 1 and the lower propeller shell 2 are connected by a first flange group 4, the first flange group 4 axially presses the upper propeller shell 1 and the lower propeller shell 2, and the first flange group 4 cooperates with the upper propeller shell 1 and the lower propeller shell 2 with a small gap to transmit torque; the control assembly 5 passes through the middle of the upper propeller shell 1 and the lower propeller shell 2, and a plurality of circumferentially distributed transverse grooves are arranged in the middle section of the control assembly 5, the support arm 3 comprises a variable pitch rocker arm 6, and the variable One end of the pitch rocker arm 6 is connected to the end of the blade metal part 9 by bolts, and the other end of the pitch rocker arm 6 is gap-matched with the transverse groove of the operating assembly 5; the operating assembly 5 rotates together with the upper propeller shell 1 and the lower propeller shell 2, and can slide up and down along the upper propeller shell 1 and the lower propeller shell 2, driving all the pitch rocker arms 6 to make circular motion around the axis of the corresponding support arm 3, realizing the total pitch change motion of the support arm, and there is a certain distance between the support arm axis of the support arm 3 and the rotor axis; the lower propeller shell 2 is connected to the motor 13 through the second flange group 12 and the motor pin 11.

[0006] Furthermore, it also includes: a fairing 14, a fairing mounting plate 15, and a plurality of fairing brackets 16, wherein the fairing mounting plate 15 is connected to the upper propeller shell 1 by bolts; the fairing bracket 16 is fixed to the lower propeller shell 2 by a first flange group 4, and the fairing 14 is connected to the fairing mounting plate 15 and the plurality of fairing brackets 16 by bolts.

[0007] Furthermore, one end of the pitch changing rocker arm 6 is connected to the blade metal part 9 by bolts and positioning pins, wherein the bolts are used to press one end of the pitch changing rocker arm 6 against the blade metal part 9, one end of the positioning pin is interference fit with the pitch changing rocker arm 6, and the other end of the positioning pin is clearance fit with the blade metal part 9 to transmit the control force to realize the blade pitch change.

[0008] Furthermore, the support arm 3 also includes: a four-point contact ball bearing 7, a split thrust ball bearing 8 and a blade metal part 9, wherein:

[0009] The middle section of the blade metal part 9 is provided with an annular boss, and the four-point contact ball bearing 7 and the split thrust ball bearing 8 are respectively arranged on both sides of the annular boss.

[0010] The inner ring of the four-point contact ball bearing 7 is interference fit with the blade metal part 9, and the outer ring of the four-point contact ball bearing 7 is clearance fit with the upper blade shell 1 and the lower blade shell 2. The distance between the end face of the four-point contact ball bearing 7 and the end face of the split thrust ball bearing 8 is smaller than the radial distance of the support arm mounting groove formed after the upper blade shell 1 and the lower blade shell 2 are installed.

[0011] The shaft ring of the split thrust ball bearing 8 is clearance-matched with the blade metal part 9 , and the seat ring of the split thrust ball bearing 8 is in contact with the upper blade shell 1 and the lower blade shell 2 .

[0012] Furthermore, the lower propeller shell 2 is connected to the motor 13 through a second flange group 12 and a motor pin 11, wherein the second flange group 12 is used to press the lower propeller shell 2 and the motor 13, one end of the motor pin 11 is interference fit with the lower propeller shell 2, and the other end of the motor pin 11 is clearance fit with the motor 13 to transmit the motor torque to realize the rotational movement of the hub.

[0013] Furthermore, the thickness of the annular shoulder can at least withstand the centrifugal force of the blade.

[0014] Furthermore, one end of the pitch rocker arm 6 is connected to the end of the blade metal member 9 by bolts, and the inner ring of the four-point contact ball bearing 7 is pressed against the annular boss.

[0015] Furthermore, oil filling holes are provided at positions corresponding to the upper bearings of the upper propeller shell 1 and the lower propeller shell 2, and oil filling nozzles are installed on the oil filling holes.

[0016] Beneficial effects:

[0017] The electric propulsion rotor hub with swing offset proposed by the present invention adopts a swing offset load reduction design method. Setting the swing offset can reduce the static load of the control by 30%; adopts a trailing edge control structure design to ensure a larger rocker arm radius and a compact structure layout; adopts fewer motion joints, has a lower design and manufacturing cost, higher reliability, and better maintainability. The electric propulsion variable collective pitch hub configuration proposed by the present invention has an axial hinge that adopts a four-point contact bearing and a split thrust bearing structure, and the collective pitch control is an internal control structure. It has a simple structure, a compact layout, and a small number of parts, which can effectively improve product reliability and reduce design and manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1A schematic diagram of a hub structure with variable collective pitch and shimmy offset according to an embodiment of the present invention;

[0019] Figure 2 This is the structural diagram of the axial hinge of the support arm;

[0020] Figure 3 Connection diagram of control components and servo;

[0021] Figure 4 Connection diagram of propeller housing and motor;

[0022] Figure 5 Connection diagram of propeller housing and fairing.

[0023] Figure 6 Schematic diagram of a shimmy offset hub.

[0024] Figure 7 It is a schematic diagram of the installation of a four-point contact ball bearing and a split thrust ball bearing;

[0025] Among them, there are an upper propeller shell 1, a lower propeller shell 2, a support arm 3, a first flange group 4, an operating assembly 5, a pitch rocker arm 6, a four-point contact ball bearing 7, a split thrust ball bearing 8, a blade metal part 9, a servo 10, a motor pin 11, a second flange group 12, a motor 13, a fairing 14, a fairing mounting plate 15, and a fairing bracket 16. DETAILED DESCRIPTION

[0026] The hub configuration used in the present invention has an axial hinge that adopts a structure of a four-point contact bearing and a split thrust bearing, which is clamped by upper and lower shells and has a simple structure and is easy to disassemble and install; the collective pitch control assembly is arranged inside the propeller shell, and the pitch change sleeve is driven up and down by the steering gear, thereby driving the five-arm pitch change rocker arm to move in a circle, thereby realizing collective pitch change control, and the structural arrangement is compact; the fairing is installed on the hub through a mounting plate and a bracket; the hub is connected with the motor through a pin and a flange to realize an integrated design.

[0027] The following is a detailed description with reference to the accompanying drawings.

[0028] like Figure 1-7 A propeller hub structure with a swing-biased variable pitch comprises an upper propeller shell 1, a lower propeller shell 2, a support arm 3, and a control assembly 5.

[0029] Among them, the upper propeller shell 1 and the lower propeller shell 2 are connected by the first flange group 4, the first flange group 4 axially presses the upper propeller shell 1 and the lower propeller shell 2, and the first flange group 4 cooperates with the upper propeller shell 1 and the lower propeller shell 2 with a small gap to transmit torque; the operating component 5 passes through the middle of the upper propeller shell 1 and the lower propeller shell 2, and the middle section of the operating component 5 is provided with a plurality of circumferentially distributed transverse grooves, and the support arm 3 includes a pitch rocker arm 6, one end of the pitch rocker arm 6 is connected to the end of the blade metal part 9 by bolts, and the other end of the pitch rocker arm 6 is gap-matched with the transverse groove of the operating component 5;

[0030] The control assembly 5 rotates together with the upper propeller shell 1 and the lower propeller shell 2, and can slide up and down along the upper propeller shell 1 and the lower propeller shell 2, driving all the variable pitch rocker arms 6 to make circular motion around the axis of the corresponding support arm 3, realizing the total pitch variable motion of the support arm, and the support arm axis of the support arm 3 is at a certain distance from the rotor axis;

[0031] The lower propeller housing 2 is connected to the motor 13 via the second flange group 12 and the motor pin 11 .

[0032] The axis of the five-arm support does not intersect with the rotor axis, but there is a certain distance between them, which is the swing offset, which can theoretically reduce the static control load by 30%.

[0033] The distance between the arm axis and the rocker arm axis is the rocker arm radius. Increasing the rocker arm radius can reduce the demand for the steering gear output control force. Due to the swing offset, the relative positions of the five arms are misaligned. Under the limited internal space, the trailing edge control structure design (rotor rotates counterclockwise when viewed from above) is adopted to ensure a larger rocker arm radius, fully utilize the internal space of the propeller shell while avoiding control interference, and the structure is compact.

[0034] Due to the swing offset, the relative positions of the five arms are misaligned. The control assembly, upper propeller shell and lower propeller shell are adaptively improved. The positions of the five grooves of the control assembly are adjusted, and the positions of the mounting holes of the upper and lower propeller shell arms are translated.

[0035] In a possible embodiment, it also includes: a fairing 14, a fairing mounting plate 15, and a plurality of fairing brackets 16, wherein the fairing mounting plate 15 is connected to the upper propeller shell 1 by bolts; the fairing bracket 16 is fixed to the lower propeller shell 2 by the first flange group 4, and the fairing 14 is connected to the fairing mounting plate 15 and the plurality of fairing brackets 16 by bolts. It is used to reduce rotor resistance and facilitate installation and disassembly.

[0036] In a possible embodiment, one end of the pitch changing rocker arm 6 is connected to the blade metal part 9 by bolts and positioning pins, wherein the bolts are used to press one end of the pitch changing rocker arm 6 against the blade metal part 9, one end of the positioning pin has an interference fit with the pitch changing rocker arm 6, and the other end of the positioning pin has a clearance fit with the blade metal part 9 to transmit the control force to achieve blade pitch change.

[0037] In a possible embodiment, the support arm 3 further includes: a four-point contact ball bearing 7, a split thrust ball bearing 8 and a blade metal part 9, wherein an annular boss is provided in the middle section of the blade metal part 9, and the four-point contact ball bearing 7 and the split thrust ball bearing 8 are respectively provided on both sides of the annular boss.

[0038] The inner ring of the four-point contact ball bearing 7 is interference fit with the blade metal part 9, and the outer ring of the four-point contact ball bearing 7 is clearance fit with the upper blade shell 1 and the lower blade shell 2. The distance between the end face of the four-point contact ball bearing 7 and the end face of the split thrust ball bearing 8 is less than the radial distance of the support arm mounting groove formed after the upper blade shell 1 and the lower blade shell 2 are installed. Figure 7 , the support arm 3 can move along the axial direction to ensure that the four-point contact ball bearing does not bear the centrifugal force load;

[0039] The shaft ring of the split thrust ball bearing 8 is clearance-matched with the blade metal part 9 , and the seat ring of the split thrust ball bearing 8 is in contact with the upper blade shell 1 and the lower blade shell 2 .

[0040] In a possible embodiment, the lower propeller housing 2 is connected to the motor 13 through a second flange group 12 and a motor pin 11, wherein the second flange group 12 is used to press the lower propeller housing 2 and the motor, one end of the motor pin 11 is interference fit with the lower propeller housing 2, and the other end of the motor pin 11 is clearance fit with the motor 13 to transmit the motor torque to realize the rotational movement of the hub.

[0041] In a possible embodiment, the thickness of the annular shoulder is at least able to withstand the centrifugal force of the blade.

[0042] In a possible embodiment, one end of the pitch rocker arm 6 is connected to the end of the blade metal member 9 by bolts, and at the same time, the inner ring of the four-point contact ball bearing 7 is pressed against the annular boss.

[0043] In a possible embodiment, oil filling holes are provided at positions corresponding to the upper bearings of the upper propeller housing 1 and the lower propeller housing 2, and oil filling nozzles are installed on the oil filling holes.

[0044] The upper paddle housing 1 and the lower paddle housing 2 provide a mounting and clamping function for the support arm 3 .

[0045] The control assembly 5 is connected to the steering gear 10 by bolts. The steering gear 10 drives the control assembly 5 to move linearly up and down relative to the propeller housing. The rocker arms of the five pitch-changing rocker arms 6 are inserted into the five grooves of the control assembly 5. The pitch-changing rocker arms 6 convert the linear motion of the control assembly 5 into circular motion around the axis of the support arm 3, driving the support arm 3 to rotate, thereby realizing synchronous pitch change of the five arms. The lower propeller housing 2 transmits the torque to the control assembly 5 through a key, driving some parts of the control assembly 5 to rotate together with the propeller housing. A double-row angular contact ball bearing is arranged inside the control assembly 5 to isolate rotating parts from non-rotating parts to prevent the steering gear from being rotated.

Claims

1. A hub structure with variable collective pitch and swing offset, characterized in that: include: An upper propeller shell (1), a lower propeller shell (2), a support arm (3), and a control assembly (5). The upper propeller shell (1) and the lower propeller shell (2) are connected by a first flange group (4), the first flange group (4) axially presses the upper propeller shell (1) and the lower propeller shell (2), and the first flange group (4) and the upper propeller shell (1) and the lower propeller shell (2) are matched with a small clearance to transmit torque; the control component (5) passes through the middle of the upper propeller shell (1) and the lower propeller shell (2), and the middle section of the control component (5) is provided with a plurality of circumferentially distributed transverse grooves, and the support arm (3) includes a pitch rocker arm (6), one end of the pitch rocker arm (6) is connected to the end of the blade metal part (9) by bolts, and the other end of the pitch rocker arm (6) is matched with the transverse groove of the control component (5) in a clearance; The control assembly (5) rotates together with the upper propeller shell (1) and the lower propeller shell (2), and can slide up and down along the upper propeller shell (1) and the lower propeller shell (2), driving all the variable pitch rocker arms (6) to perform circular motion around the axis of the corresponding support arm (3), thereby realizing the total pitch variable motion of the support arm, and the support arm axis of the support arm (3) is at a certain distance from the rotor axis; The lower propeller housing (2) is connected to the motor (13) via a second flange group (12) and a motor pin (11).

2. The variable collective pitch propeller hub structure with swing offset according to claim 1, characterized in that: Also includes: A fairing (14), a fairing mounting plate (15), and a plurality of fairing brackets (16), wherein the fairing mounting plate (15) is connected to the upper propeller shell (1) by bolts; the fairing bracket (16) is fixed to the lower propeller shell (2) by a first flange group (4); and the fairing (14) is connected to the fairing mounting plate (15) and the plurality of fairing brackets (16) by bolts.

3. The variable collective pitch propeller hub structure with swing offset according to claim 1, characterized in that: One end of the pitch-changing rocker arm (6) is connected to the blade metal part (9) through a bolt and a positioning pin, wherein the bolt is used to press one end of the pitch-changing rocker arm (6) to the blade metal part (9), one end of the positioning pin is interference-fitted with the pitch-changing rocker arm (6), and the other end of the positioning pin is clearance-fitted with the blade metal part (9) to transmit the operating force to realize the blade pitch change.

4. The variable collective pitch propeller hub structure with swing offset according to claim 1, characterized in that: The support arm (3) further comprises: a four-point contact ball bearing (7), a split thrust ball bearing (8) and a blade metal part (9), wherein: The middle section of the blade metal part (9) is provided with an annular boss, and the four-point contact ball bearing (7) and the split thrust ball bearing (8) are respectively arranged on both sides of the annular boss. The inner ring of the four-point contact ball bearing (7) is interference-fitted with the blade metal part (9), the outer ring of the four-point contact ball bearing (7) is clearance-fitted with the upper blade shell (1) and the lower blade shell (2), and the distance between the end face of the four-point contact ball bearing (7) and the end face of the split thrust ball bearing (8) is smaller than the radial distance of the support arm installation groove formed after the upper blade shell (1) and the lower blade shell (2) are installed; The shaft ring of the split thrust ball bearing (8) is clearance-matched with the blade metal part (9), and the seat ring of the split thrust ball bearing (8) is in contact with the upper blade shell (1) and the lower blade shell (2).

5. The variable collective pitch propeller hub structure with swing offset according to claim 1, characterized in that: The lower propeller housing (2) and the motor (13) are connected via a second flange group (12) and a motor pin (11), wherein the second flange group (12) is used to press the lower propeller housing (2) and the motor (13), one end of the motor pin (11) is interference-fitted with the lower propeller housing (2), and the other end of the motor pin (11) is clearance-fitted with the motor (13) to transmit motor torque to realize rotational movement of the propeller hub.

6. The variable collective pitch propeller hub structure with swing offset according to claim 1, characterized in that: The thickness of the annular shoulder is at least able to withstand the centrifugal force of the blade.

7. The variable collective pitch propeller hub structure with swing offset according to claim 1, characterized in that: One end of the pitch rocker arm (6) is connected to the end of the blade metal part (9) by bolts, and the inner ring of the four-point contact ball bearing (7) is pressed against the annular boss.

8. The variable collective pitch propeller hub structure with swing offset according to claim 1, characterized in that: Oil filling holes are arranged at positions corresponding to the upper bearings of the upper propeller shell (1) and the lower propeller shell (2), and oil filling nozzles are installed on the oil filling holes.

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