A high-low speed transmission switching device for a helicopter and its rotational speed calculation method

Abstract

The present invention discloses a high-low speed transmission switching device for a helicopter, which includes a power input shaft, a power output mechanism, and a friction clutch, a slow speed switching mechanism, a fast speed switching mechanism, a slow power transmission mechanism, and a fast power transmission mechanism arranged in a housing. One end of the power input shaft penetrates through the housing and is connected to the power input ends of the friction clutch and the slow speed switching mechanism. The slow speed switching mechanism is fixed on the fast speed switching mechanism, and the power output end of the slow speed switching mechanism is connected to the power input end of the slow power transmission mechanism. A high-low speed transmission switching device for a helicopter and its rotational speed calculation method of the present invention control and change the power transmission path of the helicopter through the cooperation of the friction clutch and the electromagnetic brake, improve the functionality of the high and low speed gear conversions of the helicopter, avoid the phenomenon of no power output during the pure mechanical conduction process, and enable the overall performance of the helicopter to be in the best state during flight.

Description

Technical Field

[0001] The present invention belongs to the technical field of helicopter variable speed, and particularly relates to a high-low speed transmission switching device for a helicopter and a rotational speed calculation method thereof. Background Art

[0002] As one of the most distinctive creations in aviation technology in the 20th century, helicopters are widely used in military, civilian and other fields due to their excellent vertical takeoff and landing, hovering in the air and low-altitude flight capabilities. With the continuous improvement of people's requirements for helicopter performance, the fixed rotor speed can no longer meet the needs of various fields. While the flight speed requirement increases, the long-term endurance ability also faces greater challenges. At present, domestic and foreign research scholars mainly change the speed of the helicopter main rotor by adjusting the output speed of the engine or adding a speed change mechanism in the main transmission system to obtain better flight performance and improve the endurance ability. However, since the working speed of the engine is relatively fixed, frequently changing the output speed will reduce the efficiency of the engine and also have a greater impact on its service life. In addition, if a speed change mechanism is added to the helicopter main transmission system, the power input of the helicopter will be temporarily interrupted during the gear shifting process, the reliability of the system will be reduced, and the possibility of accidents will increase, seriously threatening the safety of the pilot's life. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a high-low speed transmission switching device for a helicopter and a rotational speed calculation method thereof, which controls and changes the helicopter power transmission path through the cooperation of a friction clutch and an electromagnetic brake, improves the functionality of the high and low speed gear conversion of the helicopter, avoids the phenomenon of no power output in the pure mechanical conduction process, and enables the overall performance of the helicopter to be in the best state during flight.

[0004] A high-low speed transmission switching device for a helicopter includes a power input shaft, a power output mechanism, and a friction clutch, a slow rotational speed switching mechanism, a fast rotational speed switching mechanism, a slow power conduction mechanism, and a fast power conduction mechanism provided in a housing. One end of the power input shaft penetrates the housing and is connected to the power input ends of the friction clutch and the slow rotational speed switching mechanism. The slow rotational speed switching mechanism is fixed on the fast rotational speed switching mechanism. The power output end of the slow rotational speed switching mechanism is connected to the power input end of the slow power conduction mechanism. The power input end of the fast rotational speed switching mechanism is connected to the friction clutch. The fast rotational speed switching mechanism is fixed on the housing. The power output end of the fast rotational speed switching mechanism is connected to the power input end of the fast power conduction mechanism. The power output ends of the slow power conduction mechanism and the fast power conduction mechanism are connected to the power output mechanism. An electromagnetic brake is provided on the fast power conduction mechanism, and the electromagnetic brake is fixed on the housing. The power output mechanism includes a power output shaft and a rotor, and one end of the power output shaft penetrates the housing and is connected to the rotor.

[0005] Preferably, the fast rotation speed switching mechanism includes a third helical sun gear, a fourth helical sun gear, and a plurality of transmission devices. The third helical sun gear and the fourth helical sun gear are symmetrically arranged on the upper and lower sides of the transmission device. The third helical sun gear is connected to the friction clutch, and the fourth helical sun gear is connected to the slow power transmission mechanism. The transmission device includes a fixed helical gear and a fixed shaft. One end of the fixed shaft is fixedly connected to the housing, and the other end of the fixed shaft is movably connected to the fixed helical gear. The fixed helical gear meshes with the third helical sun gear and the fourth helical sun gear respectively.

[0006] Preferably, the fast power transmission mechanism includes an adjustable planet carrier, a spur sun gear, an internal gear ring, and an overrunning clutch. A plurality of spur planet gears are movably connected to the adjustable planet carrier. The spur sun gear is fixedly connected to the slow power transmission mechanism. The plurality of spur planet gears respectively mesh with the spur sun gear and the internal gear ring. The internal gear ring is connected to the overrunning clutch, and the overrunning clutch is arranged on the power output shaft.

[0007] Preferably, the slow rotation speed switching mechanism includes a first helical sun gear, a second helical sun gear, and a plurality of planetary transmission devices. The first helical sun gear and the second helical sun gear are symmetrically arranged on the upper and lower sides of the planetary transmission device. The first helical sun gear is connected to the power input shaft, and the second helical sun gear is connected to the slow power transmission mechanism. The planetary transmission device includes a planet carrier and a side planetary helical gear. The side planetary helical gear is movably connected to the planet carrier. The planet carrier is fixed to the third helical sun gear. The side planetary helical gear meshes with the first helical sun gear and the second helical sun gear respectively.

[0008] Preferably, the slow power transmission mechanism includes a switching shaft and a one-way clutch. One end of the switching shaft is connected to the second helical sun gear, and the other end of the switching shaft is connected to the power output shaft through the one-way clutch.

[0009] A method for calculating the rotation speed of a high-low speed transmission switching device of a helicopter includes a high-speed rotation state Smax of the power output shaft 81 and a low-speed rotation state Smin of the power output shaft 81;

[0010]

[0011] Wherein: S0 represents the rotation speed of the power input shaft (1), N31 represents the number of teeth of the first helical sun gear, N35 represents the number of teeth of the second helical sun gear, N63 represents the number of teeth of the spur sun gear, and N64 represents the number of teeth of the internal gear ring.

[0012] Beneficial effects:

[0013] (1) A helicopter high and low speed transmission switching device and its rotational speed calculation method of the present invention control and change the power transmission path of the helicopter through the cooperation of a friction clutch and an electromagnetic brake, improve the functionality of the high and low speed gear shifting of the helicopter, avoid the phenomenon of no power output in the pure mechanical conduction process, and make the overall performance of the helicopter in the best state during flight.

[0014] (2) A helicopter high and low speed transmission switching device and its rotational speed calculation method of the present invention have novel structure, good stability and high reliability. By designing the two speed change gear sets into a compound gear train, the smoothness of the transmission process is improved.

[0015] (3) A helicopter high and low speed transmission switching device and its rotational speed calculation method of the present invention calculate the rotational speed of the power output shaft through a formula, and at the same time determine the number of teeth of the gears used in the transmission switching device, so as to design precise gear components according to the rotational speed requirements of different power output shafts. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of the transmission switching device;

[0017] Figure 2 is an internal view of the transmission switching device;

[0018] 1 - power input shaft, 2 - friction clutch, 3 - slow speed switching mechanism, 31 - first helical sun gear, 32 - planetary transmission device, 33 - planet carrier, 34 - side planetary helical gear, 35 - second helical sun gear, 4 - fast speed switching mechanism, 41 - third helical sun gear, 42 - transmission device, 43 - fixed helical gear, 44 - fixed shaft, 45 - fourth helical sun gear, 5 - slow power conduction mechanism, 51 - switching shaft, 52 - one - way clutch, 6 - fast power conduction mechanism, 61 - adjusting planet carrier, 62 - spur planetary gear, 63 - spur sun gear, 64 - internal gear ring, 65 - overrunning clutch, 7 - electromagnetic brake, 8 - power output mechanism, 81 - power output shaft, 82 - rotor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The embodiments of the present invention will be further described below with reference to the drawings.

[0020] Embodiment 1

[0021] As Figures 1 to 2As shown in the figure; a high and low speed transmission switching device for a helicopter, comprising a power input shaft 1, a power output mechanism 8, a friction clutch 2, a slow speed switching mechanism 3, a fast speed switching mechanism 4, a slow power transmission mechanism 5 and a fast power transmission mechanism 6 arranged in a housing. One end of the power input shaft 1 penetrates the housing and is connected to the power input ends of the friction clutch 2 and the slow speed switching mechanism 3. The slow speed switching mechanism 3 is fixed on the fast speed switching mechanism 4. The power output end of the slow speed switching mechanism 3 is connected to the power input end of the slow power transmission mechanism 5. The power input end of the fast speed switching mechanism 4 is connected to the friction clutch 2. The fast speed switching mechanism 4 is fixed on the housing. The power output end of the fast speed switching mechanism 4 is connected to the power input end of the fast power transmission mechanism 6. The power output ends of the slow power transmission mechanism 5 and the fast power transmission mechanism 6 are connected to the power output mechanism 8. An electromagnetic brake 7 is arranged on the fast power transmission mechanism 6, and the electromagnetic brake 7 is fixed on the housing. The power output mechanism 8 includes a power output shaft 81 and a rotor 82. One end of the power output shaft 81 penetrates the housing and is connected to the rotor 82. The fast speed switching mechanism 4 includes a third helical sun gear 41, a fourth helical sun gear 45 and a plurality of transmission devices 42. The third helical sun gear 41 and the fourth helical sun gear 45 are symmetrically arranged on the upper and lower sides of the transmission device 42. The third helical sun gear 41 is connected to the friction clutch 2. The fourth helical sun gear 45 is connected to the slow power transmission mechanism 5. The transmission device 42 includes a fixed helical gear 43 and a fixed shaft 44. One end of the fixed shaft 44 is fixed to the housing connection. The other end of the fixed shaft 44 is movably connected to the fixed helical gear 43. The fixed helical gear 43 meshes with the third helical sun gear 41 and the fourth helical sun gear 45 respectively. The fast power transmission mechanism 6 includes an adjustable planet carrier 61, a spur sun gear 63, an internal gear ring 64 and an overrunning clutch 65. A plurality of spur planet gears 62 are movably connected to the adjustable planet carrier 61. The spur sun gear 63 is fixedly connected to the slow power transmission mechanism 5. The plurality of spur planet gears 62 respectively mesh with the spur sun gear 63 and the internal gear ring 64. The internal gear ring 64 is connected to the overrunning clutch 65. The overrunning clutch 65 is arranged on the power output shaft 81.

[0022] Power is transmitted to the power input shaft 1 through the engine. By switching the on and off states of the friction clutch 2 and the electromagnetic brake 7, the power input shaft 1 transmits power to the slow-speed switching mechanism 3 or the friction clutch 2 respectively. The power conducted through the slow-speed switching mechanism 3 is transmitted to the power output mechanism 8 through the slow-power transmission mechanism 5, causing the power output shaft 81 to drive the rotor 82 to rotate. The power transmitted through the friction clutch 2 drives the high-speed switching mechanism 4 and the high-power transmission mechanism 6 in sequence until it is transmitted to the power output mechanism 8, causing the power output shaft 81 to drive the rotor 82 to rotate. When the power output shaft 81 rotates rapidly, by closing the friction clutch 2 and opening the electromagnetic brake 7, the engine outputs counterclockwise rotating power. The counterclockwise rotating power drives the power input shaft 1 to rotate counterclockwise. The power input shaft 1 transmits the power to the third helical sun gear 41 through the closed friction clutch 2 to make it rotate. The third helical sun gear 41 drives the fixed helical gear 43 in a number of transmission devices 42 meshing with it to rotate. The fixed helical gear 43 drives the fourth helical sun gear 45 to rotate. At this time, the rotation direction of the fourth helical sun gear 45 is changed by the rotation of the fixed helical gear 43, making the counterclockwise rotating force output by the third helical sun gear 41 become the clockwise rotating force of the fourth helical sun gear 45, causing the fourth helical sun gear 45 to rotate clockwise. The fourth helical sun gear 45 drives the adjusting planet carrier 61 to rotate. A number of spur planet gears 62 on the adjusting planet carrier 61 rotate clockwise around the slow-power transmission mechanism 5 accordingly. At this time, since the spur sun gear 63 is fixed on the slow-power transmission mechanism 5 and will rotate counterclockwise with the drive of the slow-power transmission mechanism 5, when the power is output from the power input shaft 1, because the planetary transmission device 32 is fixed on the third helical sun gear 41, the side planetary helical gear 34 will rotate counterclockwise around the power input shaft 1. The cooperation of a number of planetary transmission devices 32 causes the second helical sun gear 35 to rotate counterclockwise simultaneously. The second helical sun gear 35 drives the switching shaft 51 and the spur sun gear 63 on it to rotate counterclockwise. At this time, the adjusting planet carrier 61 rotates clockwise with the fourth helical sun gear 45, and the spur sun gear 63 rotates counterclockwise. Under the combined action of the adjusting planet carrier 61 and the spur sun gear 63, the spur planet gears 62 on the adjusting planet carrier 61 drive the internal gear ring 64 to rotate clockwise while rotating clockwise around the slow-power transmission mechanism 5. The rotation speed formula of the power output shaft 81 is:

[0023] Calculate the number of teeth that effectively cooperate between each gear, and drive the overrunning clutch 65 through the inner gear ring 64, the overrunning clutch 65 drives the power output shaft 81 to rotate, and the power output shaft 81 drives the rotor 82 to rotate; the movable connections in the present invention all adopt bearing connections; wherein: S0 represents the rotation speed of the power input shaft 1, Smax represents the rotation speed of the power output shaft 81, N31 represents the number of teeth of the first helical sun gear, N35 represents the number of teeth of the second helical sun gear, N63 represents the number of teeth of the spur sun gear, and N64 represents the number of teeth of the inner gear ring.

[0024] Example 2

[0025] On the basis of Example 1, the slow speed switching mechanism 3 includes a first helical sun gear 31, a second helical sun gear 35 and a plurality of planetary transmission devices 32, wherein the first helical sun gear 31 and the second helical sun gear 35 are symmetrically arranged on the upper and lower sides of the planetary transmission device 32, the first helical sun gear 31 is connected to the power input shaft 1, the second helical sun gear 35 is connected to the slow power transmission mechanism 5, the planetary transmission device 32 includes a planet carrier 33 and a side planetary helical gear 34, the side planetary helical gear 34 is movably connected to the planet carrier 33, the planet carrier 33 is fixed on the third helical sun gear 41, and the side planetary helical gear 34 is respectively engaged with the first helical sun gear and the second helical sun gear 35; the slow power transmission mechanism 5 includes a switching shaft 51 and a one-way clutch 52, one end of the switching shaft 51 is connected to the second helical sun gear 35, and the other end of the switching shaft 51 is connected to the power output shaft 81 through the one-way clutch 52.

[0026] When the power output shaft 81 rotates slowly, the friction clutch 2 is disengaged and the electromagnetic brake 7 is turned on, so that the power of the power input shaft 1 will not be transmitted to the third helical sun gear 41, so that the electromagnetic brake 7 is in a state of locking the adjusting planet carrier 61 so that the adjusting planet carrier 61 will not rotate; the first helical sun gear 31 is driven by the power input shaft 1 to rotate counterclockwise, and the first helical sun gear 31 drives a plurality of side planetary helical gears 34 to rotate, and the side planetary helical gears 34 drive the second helical sun gear 35 to rotate. At this time, the side planetary helical gears 34 cause the second helical sun gear 35 to switch to clockwise rotation. The switching shaft 51 rotates clockwise, and the second helical sun gear 35 drives the switching shaft 51 to rotate, and the switching shaft 51 drives the one-way clutch 52 and the spur sun gear 63 to rotate. At this time, the planet carrier 61 is locked and cannot rotate, so that the spur sun gear 63 drives the spur planetary gear 62 to rotate, and the spur planetary gear 62 drives the inner ring gear 64 to rotate counterclockwise. Because the spur planetary gear 62 switches the clockwise rotation transmitted by the spur sun gear 63, the counterclockwise rotation of the inner ring gear 64 will make the overrunning clutch 65 not work, and the one-way clutch 52 will drive the power output shaft 81 to rotate; through the formula

[0027] Ensure that the transmission effect of the transmission power is in an equivalent state.

[0028] A method for calculating the rotational speed of a high-low speed transmission switching device of a helicopter, including the high-speed rotation state Smax of the power output shaft 81 and the low-speed rotation state Smin of the power output shaft 81;

[0029]

[0030] Wherein: S0 represents the rotational speed of the power input shaft 1, N31 represents the number of teeth of the first helical sun gear, N35 represents the number of teeth of the second helical sun gear, N63 represents the number of teeth of the spur sun gear, and N64 represents the number of teeth of the internal gear ring.

[0031] The specific embodiments of the present invention have been described in detail above, but they are only examples, and the present invention is not limited to the above-described specific embodiments. For those skilled in the art, any equivalent modifications and substitutions made to the present invention are also within the scope of the present invention. Therefore, equivalent transformations and modifications made without departing from the spirit and scope of the present invention are all covered by the present invention.

Claims

1. A high and low speed transmission switching device for a helicopter, characterized in that: It includes a power input shaft (1), a power output mechanism (8), a friction clutch (2), a slow speed switching mechanism (3), a fast speed switching mechanism (4), a slow power transmission mechanism (5), and a fast power transmission mechanism (6) arranged inside the housing. One end of the power input shaft (1) penetrates the housing and is connected to the power input ends of the friction clutch (2) and the slow speed switching mechanism (3). The slow speed switching mechanism (3) is fixed on the fast speed switching mechanism (4). The power output end of the slow speed switching mechanism (3) is connected to the power input end of the slow power transmission mechanism (5). The power input end of the fast speed switching mechanism (4) is connected to the friction clutch (2). The fast speed switching mechanism (4) is fixed on the housing. The power output end of the fast speed switching mechanism (4) is connected to the power input end of the fast power transmission mechanism (6). The power output ends of the slow power transmission mechanism (5) and the fast power transmission mechanism (6) are connected to the power output mechanism (8). An electromagnetic brake (7) is arranged on the fast power transmission mechanism (6), and the electromagnetic brake (7) is fixed on the housing. The power output mechanism (8) includes a power output shaft (81) and a rotor (82). One end of the power output shaft (81) penetrates the housing and is connected to the rotor (82). The fast speed switching mechanism (4) includes a third helical sun gear (41), a fourth helical sun gear (45), and several transmission devices (42). The third helical sun gear (41) and the fourth helical sun gear (45) are symmetrically arranged on the upper and lower sides of the transmission device (42). The third helical sun gear (41) is connected to the friction clutch (2). The fourth helical sun gear (45) is connected to the slow power transmission mechanism (5). The transmission device (42) includes a fixed helical gear (43) and a fixed shaft (44). One end of the fixed shaft (44) is fixed to the housing. The other end of the fixed shaft (44) is movably connected to the fixed helical gear (43). The fixed helical gear (43) meshes with the third helical sun gear (41) and the fourth helical sun gear (45) respectively. The fast power transmission mechanism (6) includes an adjustable planet carrier (61), a spur sun gear (63), an internal gear ring (64), and an overrunning clutch (65). Several spur planet gears (62) are movably connected to the adjustable planet carrier (61). The spur sun gear (63) is fixedly connected to the slow power transmission mechanism (5). The several spur planet gears (62) respectively mesh with the spur sun gear (63) and the internal gear ring (64). The internal gear ring (64) is connected to the overrunning clutch (65). The overrunning clutch (65) is arranged on the power output shaft (81).The slow rotation speed switching mechanism (3) includes a first helical sun gear (31), a second helical sun gear (35) and a plurality of planetary transmission devices (32). The first helical sun gear (31) and the second helical sun gear (35) are symmetrically arranged on the upper and lower sides of the planetary transmission device (32). The first helical sun gear (31) is connected to the power input shaft (1), and the second helical sun gear (35) is connected to the slow power transmission mechanism (5). The planetary transmission device (32) includes a planetary carrier (33) and a side planetary helical gear (34). The side planetary helical gear (34) is movably connected to the planetary carrier (33). The planetary carrier (33) is fixed on the third helical sun gear (41). The side planetary helical gear (34) meshes with the first helical sun gear and the second helical sun gear (35) respectively. The slow power transmission mechanism (5) includes a switching shaft (51) and a one-way clutch (52). One end of the switching shaft (51) is connected to the second helical sun gear (35), and the other end of the switching shaft (51) is connected to the power output shaft (81) through the one-way clutch (52). Among them, the engine delivers power to the power input shaft (1). By switching the on and off states of the friction clutch (2) and the electromagnetic brake (7), the power input shaft (1) delivers power to the slow speed switching mechanism (3) or the friction clutch (2) respectively. The power conducted through the slow speed switching mechanism (3) will be conducted to the power output mechanism (8) through the slow power conduction mechanism (5), causing the power output shaft (81) to drive the rotor (82) to rotate. The power delivered through the friction clutch (2) will drive the high speed switching mechanism (4) and the high power conduction mechanism (6) in sequence until it is conducted to the power output mechanism (8), causing the power output shaft (81) to drive the rotor (82) to rotate. When the power output shaft (81) rotates rapidly, by closing the friction clutch (2) and opening the electromagnetic brake (7), the engine delivers counterclockwise rotating power. The counterclockwise rotating power drives the power input shaft (1) to rotate counterclockwise. The power input shaft (1) delivers power to the third helical sun gear (41) through the closed friction clutch (2) to make it rotate. The third helical sun gear (41) drives the fixed helical gear (43) in several transmission devices (42) meshing with it to rotate. The fixed helical gear (43) drives the fourth helical sun gear (45) to rotate. At this time, the rotation direction of the fourth helical sun gear (45) is changed by the rotation of the fixed helical gear (43), making the counterclockwise rotating force output by the third helical sun gear (41) become the clockwise rotating force of the fourth helical sun gear (45), causing the fourth helical sun gear (45) to rotate clockwise. The fourth helical sun gear (45) drives the adjusting planet carrier (61) to rotate. Several spur planet gears (62) on the adjusting planet carrier (61) rotate clockwise around the slow power conduction mechanism (5) accordingly. At this time, since the spur sun gear (63) is fixed on the slow power conduction mechanism (5) and will rotate counterclockwise with the drive of the slow power conduction mechanism (5), when the power is output from the power input shaft (1), because the planetary transmission device (32) is fixed on the third helical sun gear (41), the side planetary helical gear (34) will rotate counterclockwise around the power input shaft (1). The cooperation of several planetary transmission devices (32) will cause the second helical sun gear (35) to move counterclockwise simultaneously. The second helical sun gear (35) drives the switching shaft (51) and the spur sun gear (63) on it to move counterclockwise. At this time, the adjusting planet carrier (61) rotates clockwise with the fourth helical sun gear (45), and the spur sun gear (63) rotates counterclockwise. Under the combined action of the adjusting planet carrier (61) and the spur sun gear (63), the spur planet gears (62) on the adjusting planet carrier (61) drive the internal gear ring (64) to rotate clockwise while rotating clockwise around the slow power conduction mechanism (5).

2. A method for calculating the rotational speed of a high-low speed transmission switching device of a helicopter, which is applied to the high-low speed transmission switching device of a helicopter as described in claim 1, and is characterized in that: It includes the high-speed rotation state Smax of the power output shaft (81) and the low-speed rotation state Smin of the power output shaft (81); Wherein: S0 represents the rotational speed of the power input shaft (1), N31 represents the number of teeth of the first helical sun gear, N35 represents the number of teeth of the second helical sun gear, N63 represents the number of teeth of the spur sun gear, and N64 represents the number of teeth of the internal gear ring.

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