CN104896049B - Mini-type dual-power aircraft bearing speed reduction device - Google Patents

Abstract

The invention belongs to the technical field of aircraft design and discloses a mini-type dual-power aircraft bearing speed reduction device. The mini-type dual-power aircraft bearing speed reduction device adopts two structures composed of inner friction rings, hollow pin rollers, solid pin rollers and speed reduction machine frames to form the structures which are similar to cylindrical roller bearings and are symmetrically arranged on the two sides of the center of an outer shell, output shafts of two motors are fixedly connected with input shafts through couplers, the input shafts are movably connected with holes of a shell through bearings, are movably connected with center holes of the speed reduction machine frames through another bearings and are fixedly connected with center holes of the inner friction rings, a belt wheel I is movably connected with a belt wheel II through a belt, a center hole of the belt wheel II is fixedly connected with the inner end of a shaft, and the outer end of the shaft is fixedly connected with a center hole of a wing plate. The mini-type dual-power aircraft bearing speed reduction device can achieve a large reduction ratio; if multiple cylindrical roller bearing structures are connected in series, a larger reduction ratio can be achieved, and the weight is not obviously increased; as usage of a clutch is avoided, the cost and weight are both reduced. The mini-type dual-power aircraft bearing speed reduction device is suitable for mini-type aircrafts.

Description

Bearing deceleration device for miniature dual-powered aircraft

technical field

The invention belongs to the technical field of aircraft design, and in particular relates to a deceleration and power mixing device applied to light aircraft.

Background technique

For a long time, the engine devices of various aircraft equipment have been replaced regularly for safety considerations. And for safety considerations, usually its safety factor is set relatively large, and the engine has been replaced before reaching its maximum use time limit, the cost is high, and the equipment is not fully used.

After that, dual power output aircraft appeared. For example, the invention patent application "Dual Power Output Aircraft" with application number 201420397029.3 disclosed a relatively advanced aircraft with dual engine output power. The shaft device Ⅰ is fixedly connected to the pulley shaft, and the pulley shaft is fixedly connected to the pulley Ⅰ, and the pulley Ⅰ is movably connected to the pulley Ⅱ fixedly connected to the support shaft Ⅲ through the belt Ⅰ; the output shaft of the engine Ⅱ is fixed to the sun gear shaft through the spline coupling Ⅱ. The center shaft of the planetary gear carrier is fixedly connected to the belt pulley III, and the belt pulley III is movably connected to the pulley IV through the belt II; the belt pulley IV is fixedly connected to the outside of the bevel gear shaft, and the inner end of the bevel gear shaft is fixedly connected to the bevel gear. The gear meshes with the lower bevel gear; the lower end of the inner shaft is fixed to the lower bevel gear, the upper end of the inner shaft is fixed to the upper rotor; the upper end of the transmission sleeve is fixed to the lower rotor, the lower end of the transmission sleeve is fixed to the upper bevel gear, and the transmission sleeve is sleeved on the inner shaft Middle part; the aircraft can enhance the safety of small flight equipment, increase the utilization rate and service life of engine equipment, reduce the operating cost of the aircraft, has a simple structure, is easy to implement, and can realize a deceleration mechanism at the same time.

However, in its implementation, it can be found that although the dual-power realization form is adopted, in order to achieve the purpose, the planetary gear structure is adopted, the structure size is large and the weight is heavy, it is not suitable for the design of micro air vehicles, and is limited by the size of the planetary gear. The impact, the reduction ratio is small.

Contents of the invention

The object of the present invention is to provide a dual power output device applied to a micro-aircraft. When the dual power is realized, the weight of the device is as light and small as possible, and the transmission with a large reduction ratio can be realized. At the same time, even if the clutch is not used, when one motor is stuck due to a fault, the other motor can also drive the equipment to run normally.

The present invention consists of motor I1, coupling I2, input shaft I3, casing 4, retainer I5, deceleration rack I6, hollow roller I7, bearing bush I8, planetary carrier I9, pulley I10, planetary carrier II11, hollow roller Ⅱ12, reducer frame Ⅱ13, bearing bush Ⅱ14, input shaft Ⅱ15, retainer Ⅱ16, coupling Ⅱ17, motor Ⅱ18, friction inner ring Ⅰ19, hollow roller Ⅲ20, bearing bush Ⅲ21, belt 22, pulley Ⅱ23, shaft 24, wing Disc 25, bearing bush Ⅳ 26, hollow roller Ⅳ 27, friction inner ring Ⅱ 28, solid roller Ⅰ 29a and solid roller Ⅱ 29b, in which the output shaft of motor Ⅰ 1 is fixedly connected with input shaft Ⅰ 3 through coupling Ⅰ 2 , and input shaft Ⅰ 3 is from the right To the left, it is movably connected with the hole Ⅳ33 of the casing 4 through the bearing Ⅳd, movably connected with the center hole of the stopper Ⅰ5, movably connected with the center hole of the reduction frame Ⅰ6 through the bearing Ⅲc, and fixedly connected with the center hole of the friction inner ring Ⅱ28; deceleration The size and shape of the circular axis surface I37 of the frame I6 match the size and shape of the arc surface I40 of the bearing bush I8 and the arc surface II42 of the bearing bush IV26.

Hollow roller Ⅰ7, 4 identical solid rollers Ⅰ29a, hollow roller Ⅳ27 and another 4 identical solid rollers Ⅰ29a are arranged in sequence, placed on the outer ring of the friction inner ring Ⅱ28 and the circular shaft surface Ⅱ38 of the reduction frame Ⅰ6 Between, and rolling connection with the outer ring of the friction inner ring II28 and the circular shaft surface II38 of the reduction frame I6.

The shaft III45 of the planetary carrier I9 is fixedly connected to the right side of the central through hole of the pulley I10, the shaft I43 of the planetary carrier I9 is connected with the center hole of the hollow roller IV27, and the shaft II44 of the planetary carrier I9 is connected to the center of the hollow roller I7. Hole active connection.

The output shaft of the motor II18 is fixedly connected to the input shaft II15 through the coupling II17, and the input shaft II15 is flexibly connected to the hole VII36 of the housing 4 through the bearing Ia from left to right, to the center hole of the retainer II16, and to the center hole of the block IIb through the bearing IIb. The center hole of the reduction frame II13 is movably connected with the center hole of the friction inner ring I19; the size and shape of the circular shaft surface III46 of the reduction frame II13 is the size and shape of the arc surface III49 of the bearing bush II14 and the arc surface VI51 of the bearing bush III21 match.

Hollow roller Ⅱ12, 4 identical solid rollers Ⅱ29b, hollow roller Ⅲ20 and another 4 identical solid rollers Ⅱ29b are arranged in sequence, placed on the outer ring of the friction inner ring Ⅰ19 and the circular shaft surface Ⅳ47 of the reduction frame Ⅱ13 Between, and rolling connection with the outer ring of the friction inner ring I19 and the circular axis surface IV47 of the reduction frame II13.

The shaft Ⅵ54 of the planetary carrier Ⅱ11 is fixedly connected with the left side of the central through hole of the pulley Ⅰ10, the shaft Ⅳ52 of the planetary carrier Ⅱ11 is connected with the center hole of the hollow roller Ⅲ20, and the shaft Ⅴ53 of the planetary carrier Ⅱ11 is connected with the center of the hollow roller Ⅱ12. Hole active connection.

Pulley I10 is flexibly connected to pulley II23 through belt 22; the central hole of pulley II23 is fixedly connected to the inner end of shaft 24, and the outer end of shaft 24 is fixedly connected to the central hole of wing disc 25.

The inside of the hole IV33 side of the casing 4 is fixedly connected with the stopper I5, the inside of the hole VII36 side of the casing 4 is fixedly connected with the stopper II16, the hole I30 of the casing 4 is flexibly connected with the raised end VI50 of the bearing bush III21, and the hole III32 of the casing 4 is connected with the The raised end II41 of the bearing bush IV26 is movably connected, the hole V34 of the casing 4 is movably connected with the raised end I39 of the bearing bush I8, and the hole VI35 of the casing 4 is movably connected with the raised end III48 of the bearing bush II14.

The main working process of a kind of miniature dual-power aircraft bearing deceleration device of the present invention is as follows:

Taking the power on the right side as an example, the motor I1 is connected to the input shaft I3 through the coupling I2, driving the friction inner ring II28 to rotate, the friction inner ring II28, the hollow roller I7, the hollow roller IV27, 8 solid rollers I29a and the reducer Frame Ⅰ6 forms a cylindrical roller bearing structure. When the bearing bush Ⅰ8 and bearing bush Ⅳ26 are pressed against the reduction frame Ⅰ6, the reduction frame Ⅰ6 is fixed, and the friction inner ring Ⅱ28 drives the hollow roller Ⅰ7, hollow roller Ⅳ27 and 8 through friction. A solid roller Ⅰ29a rotates around its own axis, and at the same time, its own rotation drives the hollow roller Ⅰ7, hollow roller Ⅳ27 and 8 solid rollers Ⅰ29a to rotate around the axis of the friction inner ring Ⅱ28 along the outer circular axial surface of the friction inner ring Ⅱ28 The planet carrier I9 extracts the effective revolution motion to realize the deceleration of the mechanism, and the reduction ratio R is equal to 1+(the outer diameter of the frame I6/the inner diameter of the friction inner ring II28). At the same time, if a cylindrical roller bearing structure composed of friction inner ring Ⅱ28, hollow roller Ⅰ7, hollow roller Ⅳ27, 8 solid rollers Ⅰ29a and reduction frame Ⅰ6 is connected in series, a larger reduction ratio can be achieved, and the reduction The ratio is R to the Nth power, N is the number of cylindrical roller bearing structures in series, the size is small, and the weight increase is not obvious.

Then the planet carrier I9 drives the pulley I10 to rotate, and the power is transmitted to the wing disc 25 through the belt 22, the pulley II 23 and the shaft 24 in turn, and the wing disc 25 rotates to provide the power of the aircraft.

The realization process of the left power is similar to that of the right power, the only difference is that the rotation direction of the motor II18 is opposite to that of the motor I1.

When working on the right side, the external motor drives bearing bush I8 and bearing bush IV26 to press against the reduction frame I6 to fix the reduction frame I6; the friction inner ring II28 rotates to drive the hollow roller I7, hollow roller IV27, and 8 solid rollers. The column I29a moves along the inner axial surface of the fixed reduction frame I6 to achieve deceleration, and then drives the movement of the planet carrier I9, and the planet carrier I9 drives the pulley I10 to rotate.

When working on the left side, the external motor drives the bearing bush II14 and bearing bush III21 to press against the reduction frame II13 to fix the reduction frame II13; the friction inner ring I19 rotates to drive the hollow roller II12, hollow roller III20 and 8 solid rollers The column II29b moves along the inner axial surface of the fixed reduction frame II13 to achieve deceleration, and then drives the movement of the planet carrier II11, and the planet carrier II11 drives the pulley I10 to rotate. Solid roller Ⅰ29a, solid roller Ⅱ29b

When the left and right sides work at the same time, the external motor drives the bearing bush I8 and the bearing bush IV26 to be pressed against the reduction frame I6, the bearing bush II14 and the bearing bush III21 are pressed against the reduction frame II13, and the rotation directions of the motor I1 and the motor II18 are opposite to drive The rotation of the wing disc 25.

When only the left side works and the motor I1 on the right side is stuck due to a fault, driven by the external motor, the bearing bush II14 and the bearing bush III21 are pressed against the reduction frame II13, and the bearing bush I8 and IV26 are not pressed against the reduction frame I6 , as mentioned above, the motor II18 drives the pulley I10 to rotate, the pulley I10 drives the planet carrier I9 to rotate, the bearing bush I8 and the bearing bush IV26 are not pressed against the reduction frame I6, and the reduction frame I6 is movable. According to the nature of the cylindrical roller bearing structure , the friction inner ring Ⅱ28 is fixed due to the stuck motor Ⅰ1 due to a solid connection fault, and the planet carrier Ⅰ9 drives the hollow roller Ⅰ7, hollow roller Ⅳ27 and 8 solid rollers Ⅰ29a to move through friction, and then drives the rotation of the reduction frame Ⅰ6, Therefore, 1 that is stuck due to a fault does not affect the normal operation of the equipment. When only the right side is working, and the motor II 18 on the left side is stuck due to a fault, the operation process is the same.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

1. Large reduction ratio can be realized. Friction inner ring Ⅱ28, hollow roller Ⅰ7, hollow roller Ⅳ27, solid roller Ⅰ29a and reduction frame Ⅰ6 form a cylindrical roller bearing structure, and the reduction ratio R is equal to 1+(outer diameter of frame Ⅰ6/friction inner ring Ⅱ28 inner diameter). At the same time, a cylindrical roller bearing structure composed of friction inner ring Ⅱ28, hollow roller Ⅰ7, hollow roller Ⅳ27, 8 solid rollers Ⅰ29a and reduction frame Ⅰ6 can be connected in series to achieve a larger reduction ratio and reduce The ratio is the Nth power of R, and N is the number of cylindrical roller bearing structures connected in series.

2. The weight of the equipment is lighter than that of existing structures, and is suitable for micro-aircraft. Friction inner ring Ⅱ28, hollow roller Ⅰ7, hollow roller Ⅳ27, 8 solid rollers Ⅰ29a and reduction frame Ⅰ6 form a reduction mechanism of cylindrical roller bearing structure, which is light in weight. Simultaneously connecting multiple cylindrical roller bearing structures mentioned above in series can achieve a larger reduction ratio while the mass increase is not obvious.

3. Avoid the use of clutches, reduce costs, and reduce the inherent quality of equipment. According to the nature of the cylindrical roller bearing structure, when only one side works and the motor on the other side is stuck due to a fault, the bearing bush on the faulty side will not be pressed against the reducer frame driven by the external motor. According to the cylindrical roller bearing structure The nature of the friction inner ring on the fault side is fixed by the engine that is stuck due to the fault, and the planet carrier on this side drives the solid roller and the hollow roller to move through friction, and then drives the rotation of the deceleration frame, so the fault is stuck. The motor does not affect the normal operation of the equipment.

Description of drawings

Figure 1 is a structural schematic diagram of the bearing deceleration device of a miniature dual-powered aircraft

Figure 2 is a sectional view of A-A in Figure 1

Figure 3 is a cross-sectional view of B-B in Figure 1

Fig. 4 is the structural representation of housing 4

Figure 5 is a schematic diagram of the structure of the reduction frame I6

Figure 6 is a schematic diagram of the structure of the bearing bush I8

Figure 7 is a schematic diagram of the structure of the bearing bush IV26

Figure 8 is a schematic diagram of the structure of the planet carrier I9

Figure 9 is a structural schematic diagram of the reduction rack II 13

Figure 10 is a schematic diagram of the structure of the bearing bush II14

Figure 11 is a schematic diagram of the structure of the planet carrier II11

Figure 12 is a schematic diagram of the structure of the bearing bush III 21

Among them: a. Bearing Ⅰ b. Bearing Ⅱ c. Bearing Ⅲ d. Bearing Ⅳ 1. Motor Ⅰ 2. Coupling Ⅰ 3. Input shaft Ⅰ 4. Shell 5. Block Ⅰ 6. Reducer frame Ⅰ 7. Hollow roller Column Ⅰ 8. Bearing bush Ⅰ 9. Planetary carrier Ⅰ 10. Pulley Ⅰ 11. Planetary carrier Ⅱ 12. Hollow roller Ⅱ 13. Reduction frame Ⅱ 14. Bearing bush Ⅱ 15. Input shaft Ⅱ 16. Block plate Ⅱ 17. Coupling Device Ⅱ 18. Motor Ⅱ 19. Friction inner ring Ⅰ 20. Hollow roller Ⅲ 21. Bearing bush Ⅲ 22. Belt 23. Pulley Ⅱ 24. Shaft 25. Wing disc 26. Bearing bush Ⅳ 27. Hollow roller Ⅳ 28. Friction Inner ring II 29a. Solid roller I 29b. Solid roller II 30. Hole I 31. Hole II 32. Hole III 33. Hole IV 34. Hole V 35. Hole VI 36. Hole VII 37. Round shaft surface I 38 .Circular shaft surface II 39. Raised end I 40. Arc surface I 41. Raised end II 42. Arc surface II 43. Shaft I 44. Shaft II 45. Shaft III 46. Round shaft face III 47. Round shaft face Ⅳ 48. Raised end Ⅲ 49. Arc surface Ⅲ 50. Raised end Ⅵ 51. Arc surface Ⅵ 52. Shaft Ⅳ 53. Shaft Ⅴ 54. Shaft Ⅵ

detailed description

Embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1, the present invention consists of motor I1, coupling I2, input shaft I3, casing 4, block plate I5, reduction frame I6, hollow roller I7, bearing bush I8, planet carrier I9, pulley I10, planet Frame Ⅱ11, Hollow Roller Ⅱ12, Reducer Frame Ⅱ13, Bearing Ⅱ14, Input Shaft Ⅱ15, Block Ⅱ16, Coupling Ⅱ17, Motor Ⅱ18, Friction Inner Ring Ⅰ19, Hollow Roller Ⅲ20, Bearing Ⅲ21, Belt 22, Pulley Ⅱ23, shaft 24, wing disc 25, bearing bush Ⅳ26, hollow roller Ⅳ27, friction inner ring Ⅱ28, solid roller Ⅰ29a and solid roller Ⅱ29b, in which the output shaft of motor Ⅰ1 is fixedly connected with input shaft Ⅰ3 through coupling Ⅰ2 , the input shaft Ⅰ3 is movably connected with the hole Ⅳ33 of the casing 4 through the bearing Ⅳd from right to left, movably connected with the center hole of the block plate Ⅰ5, movably connected with the center hole of the reduction frame Ⅰ6 through the bearing Ⅲc, and movably connected with the friction inner ring Ⅱ28 The center hole is fixed; the size and shape of the circular axis surface I37 of the reduction frame I6 match the size and shape of the arc surface I40 of the bearing bush I8 and the arc surface II42 of the bearing bush IV26.

As shown in Figure 2, the hollow roller I7, four identical solid rollers I29a, hollow roller IV27 and the other four identical solid rollers I29a are arranged in sequence, placed on the outer ring of the friction inner ring II28 and the reduction frame between the circular shaft surfaces II38 of I6, and are rollingly connected with the outer ring of the friction inner ring II28 and the circular shaft surface II38 of the reduction frame I6.

The shaft III45 of the planetary carrier I9 is fixedly connected to the right side of the central through hole of the pulley I10, the shaft I43 of the planetary carrier I9 is connected with the center hole of the hollow roller IV27, and the shaft II44 of the planetary carrier I9 is connected to the center of the hollow roller I7. Hole active connection.

The output shaft of the motor II18 is fixedly connected to the input shaft II15 through the coupling II17, and the input shaft II15 is flexibly connected to the hole VII36 of the housing 4 through the bearing Ia from left to right, to the center hole of the retainer II16, and to the center hole of the block IIb through the bearing IIb. The center hole of the reduction frame II13 is movably connected with the center hole of the friction inner ring I19; the size and shape of the circular shaft surface III46 of the reduction frame II13 is the size and shape of the arc surface III49 of the bearing bush II14 and the arc surface VI51 of the bearing bush III21 match.

As shown in Figure 3, the hollow roller II12, four identical solid rollers II29b, hollow roller III20 and the other four identical solid rollers II29b are arranged in sequence, placed on the outer ring of the friction inner ring I19 and the reduction frame Between the circular axis surface IV47 of II13, it is rollingly connected with the outer ring of the friction inner ring I19 and the circular axis surface IV47 of the reduction frame II13.

The shaft Ⅵ54 of the planetary carrier Ⅱ11 is fixedly connected with the left side of the central through hole of the pulley Ⅰ10, the shaft Ⅳ52 of the planetary carrier Ⅱ11 is connected with the center hole of the hollow roller Ⅲ20, and the shaft Ⅴ53 of the planetary carrier Ⅱ11 is connected with the center of the hollow roller Ⅱ12. Hole active connection.

Pulley I10 is flexibly connected to pulley II23 through belt 22; the central hole of pulley II23 is fixedly connected to the inner end of shaft 24, and the outer end of shaft 24 is fixedly connected to the central hole of wing disc 25.

The inside of the hole IV33 side of the casing 4 is fixedly connected with the stopper I5, the inside of the hole VII36 side of the casing 4 is fixedly connected with the stopper II16, the hole I30 of the casing 4 is flexibly connected with the raised end VI50 of the bearing bush III21, and the hole III32 of the casing 4 is connected with the The raised end II41 of the bearing bush IV26 is movably connected, the hole V34 of the casing 4 is movably connected with the raised end I39 of the bearing bush I8, and the hole VI35 of the casing 4 is movably connected with the raised end III48 of the bearing bush II14.

The outer circular shaft surface of friction inner ring II28, the circular shaft surface I37 of reduction frame I6, the arc surface I40 of bearing bush I8 and the arc surface II42 of bearing bush IV26 all have friction surfaces to realize mutual speed and force transmission .

Claims (1)

1. A light dual-power aircraft bearing deceleration device is characterized in that it consists of motor I (1), shaft coupling I (2), input shaft I (3), housing (4), retaining plate I (5), deceleration Frame I (6), Hollow Roller I (7), Bearing I (8), Planetary Carrier I (9), Pulley I (10), Planetary Carrier II (11), Hollow Roller II (12), Reducer frame II (13), bearing bush II (14), input shaft II (15), block plate II (16), coupling II (17), motor II (18), friction inner ring I (19), Hollow roller III (20), bearing bush III (21), belt (22), pulley II (23), shaft (24), wing disc (25), bearing bush IV (26), hollow roller IV (27) , friction inner ring II (28), solid roller I (29a) and solid roller II (29b), in which the output shaft of motor I (1) is connected to the input shaft I (3) through coupling I (2) Fixed connection, the input shaft I (3) is flexibly connected with the hole IV (33) of the housing (4) through the bearing IV (d) from right to left, flexibly connected with the center hole of the block I (5), and through the bearing III ( c) Flexible connection with the center hole of the reduction frame I (6), fixed connection with the center hole of the friction inner ring II (28); the size and shape of the circular shaft surface I (37) of the reduction frame I (6) and the bearing bush The size and shape of the arc surface I (40) of I (8) and the arc surface II (42) of the bearing bush IV (26) match; the hollow roller I (7), 4 identical solid rollers I (29a), The hollow roller IV (27) and the other 4 identical solid rollers I (29a) are arranged sequentially, placed on the outer ring of the friction inner ring II (28) and the circular shaft surface II (38) of the reduction frame I (6). ), and rolling connection with the outer ring of the friction inner ring II (28) and the circular shaft surface II (38) of the reduction frame I (6); the shaft III (45) of the planet carrier I (9) and the pulley The right side of the central through hole of I (10) is fixedly connected, the shaft I (43) of the planet carrier I (9) is movably connected with the center hole of the hollow roller IV (27), and the shaft II of the planet carrier I (9) ( 44) is movably connected with the center hole of the hollow roller Ⅰ (7); the output shaft of the motor Ⅱ (18) is fixedly connected with the input shaft Ⅱ (15) through the coupling Ⅱ (17), and the input shaft Ⅱ (15) starts from the left To the right through the bearing Ⅰ (a) and the hole VII (36) of the housing (4) is movably connected, and the center hole of the baffle II (16) is movably connected, and through the bearing Ⅱ (b) and the reduction frame Ⅱ (13) The central hole is movably connected to the central hole of the friction inner ring I (19); the size and shape of the circular shaft surface III (46) of the reduction frame II (13) is the same as the arc surface III (49) of the bearing bush II (14) Match the size and shape of the arc surface VI (51) of the bearing bush III (21); hollow roller II (12), 4 identical solid roller II (29b), hollow roller III (20) and the other 4 The same solid rollers II (29b) are arranged in sequence, placed between the outer ring of the friction inner ring I (19) and the circular axis surface IV (47) of the reduction frame II (13), and are connected to the friction inner ring I ( 19 ) and the circular shaft surface IV (47) of the reduction frame II (13) are rollingly connected; the shaft VI (54) of the planet carrier II (11) is fixed to the left side of the central through hole of the pulley I (10) Then, the shaft IV (52) of the planetary carrier II (11) is movably connected with the center hole of the hollow roller III (20), and the shaft V (53) of the planetary carrier II (11) is connected with the center of the hollow roller II (12). The holes are flexibly connected; the pulley I (10) is flexibly connected with the pulley II (23) through the belt (22); the central hole of the pulley II (23) is fixedly connected to the inner end of the shaft (24), and the outer end of the shaft (24) It is fixedly connected with the center hole of the wing disc (25); the inside of the hole IV (33) side of the shell (4) is fixedly connected with the stop piece I (5), and the inside of the hole VII (36) side of the shell (4) is connected with the stop piece II (16) Fixed connection, the hole I (30) of the shell (4) is flexibly connected with the raised end VI (50) of the bearing bush III (21), and the hole III (32) of the shell (4) is connected with the bearing bush IV (26) The raised end II (41) is flexibly connected, the hole V (34) of the shell (4) is flexibly connected with the raised end I (39) of the bearing bush I (8), and the hole VI (35) of the shell (4) is connected with the bearing bush II The protruding end III (48) of (14) is flexibly connected.