RU2613099C1 - Main reduction gear of helicopter - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: invention is relevant to mechanical engineering, namely, to the main four-stage non-planetary reduction gear of helicopter. Helicopter reduction gear is provided with two transmission paths of torque supplied by two driving engines (1) to joint driven wheel (2) for shaft drive (3) of rotor and to joint driven wheel (4) for shaft drive (5) of anti-torque tail rotor. Each of lines provides four stage of reduction. Driving gear (13) of the third stage placed on the third shaft (12), the first pair of driven wheels (14) of the third stage engaged with the said gear (13) and the second pair of driven wheels (14) of the third stage connected to the first pair with the aid of idler gears (16) are mounted on the third stage of reduction. Four driving gears (17) of the fourth stage mounted on shafts (15) of rotation of driven wheels (14) of the third stage and engaged with joint driven wheel (2) of rotor shaft (3) is provided for on the fourth reduction stage. The second shaft (9) of each mentioned lines is linked with drive (22) of helicopter accessory gear-box. Moreover, driving gear (18) for shaft drive is mounted on the second shaft (9).

EFFECT: invention decreases reduction-gear weight as well as reduces degradation of rolling bearings of shafts.

4 cl, 1 dwg, 1 tbl

Description

The invention relates to the field of mechanical engineering, namely to the main gearboxes of a helicopter, designed to transmit torque from one or more driven gas turbine engines to the main and tail rotors, with a corresponding change in the magnitude of the transmitted moment, direction and frequency of rotation, as well as for the drive of helicopter assemblies ( fans, generator, hydraulic pump, etc.) mounted on the main gearbox.

For the main gearbox of the helicopter, its weight is of fundamental importance, which should be minimal for the selected helicopter layout. The mass of the gearbox to a large extent depends on the selected kinematic scheme.

The closest analogue of the claimed invention is a multi-stage gearbox disclosed in the patent of the Russian Federation RU 2146636, 03.20.2000. The specified gearbox contains two transmission lines of torque from two drive motors to a common driven wheel to drive the rotor shaft. Each of the lines has several stages, and at the penultimate stage, the transmitted torque from each engine is divided into two streams, for which the drive gear of the second stage is connected to a pair of driven wheels mounted on separate shafts. At the same time, driving gears of the output stage are placed on these shafts, which transmit torque to the common driven wheel of the rotor shaft. Thus, in the known gearbox provides separation of the torques transmitted from two engines into four streams to ensure the reliability of the gearbox. The disadvantage of this gearbox is its large mass, as well as the limited application associated with the ability to drive only the rotor of the helicopter.

The objective of the invention is the creation of a multi-threaded non-planetary gearbox of a helicopter, providing the transmission of torque from two drive engines to a common driven wheel to drive the rotor, as well as a common driven wheel to drive the tail rotor.

The technical result of the invention is to reduce the weight of the gearbox, as well as reducing the wear of roller bearings of the shafts.

The specified technical result is achieved in the claimed invention due to the fact that the gearbox includes two lines for transmitting torque from two drive motors to a common driven wheel for driving the rotor shaft and a common driven wheel for driving the tail rotor shaft, each of which contains:

a drive gear of the first stage mounted on the first input shaft associated with the engine, and a driven wheel of the first stage mounted on the second shaft and engaged with said drive gear,

the drive gear of the second stage mounted on the second shaft, and being in mesh with the driven wheel of the second stage mounted on the third shaft,

a third stage drive gear mounted on the third shaft, a first pair of third stage driven wheels engaged with said gear, and a second pair of third stage driven wheels connected to the first pair via spurious gears,

four driving gears of the fourth stage mounted on the shafts of rotation of the driven wheels of the third stage and meshed with the common driven wheel of the rotor shaft,

at the same time, in each of the indicated lines, the second shaft is connected to the drive of the helicopter’s aggregate box, and a drive gear for driving the tail rotor shaft is installed on the second shaft.

The specified technical result is also achieved in private embodiments of the invention due to the fact that:

- the driving gears of the first, third and fourth stages, as well as the driven wheels of the first and third stages are made cylindrical, and the driving gears and driven wheels of the second stage are made conical,

- pinion gears for driving the tail shaft of each line are tapered,

- in each line, the drive gear for driving the tail shaft is engaged with the driven bevel gear of the tail shaft mounted on the additional shaft, and on the additional shaft there is also an additional bevel gear for driving the tail shaft meshed with the common driven wheel for driving tail shaft.

The main difference between the claimed invention and the known analogues using non-planetary kinematic schemes is that in the third stage of reduction of the claimed device using spurious gears, each stream of power from each drive motor is divided into four streams, which are converted into eight streams in the fourth stage of reduction , summing up on one common wheel that transmits torque to the rotor, which reduces the weight of the gearbox, as well as reduce the load on the bearings and roller shafts in the fourth stage.

The invention is illustrated by figure 1, which shows the basic kinematic system of the claimed gear.

The claimed gearbox has a multi-threaded non-planetary scheme using cylindrical gears of external gearing, as well as bevel gears. In this case, the gearbox contains two transmission lines of torque from two drive motors (1) to a common driven wheel (2) to drive the rotor shaft (3), as well as to a common driven wheel (4) to drive the tail rotor shaft (5).

Each line includes four stages of reduction.

In the first stage, each line has a leading cylindrical gear (6) of the first stage mounted on the first input shaft (7) connected to the engine (1), and the driven cylindrical wheel (8) of the first stage mounted on the second shaft is engaged with it (9). In this case, the first and second shafts in each line are mounted essentially in parallel.

A second bevel gear (10) of the second stage, mounted on the second shaft (9), and a driven bevel wheel (11) of the second stage located on the third shaft (12), which is in mesh with it, are installed on the second stage. In this case, the third shaft (12) is located at an angle to the second shaft (9).

At the third stage, a leading cylindrical gear (13) of the third stage is installed, located on the third shaft (12), and four driven cylindrical wheels (14), each of which rotates on a separate shaft (15) (fourth shaft). In this case, the first pair of driven wheels (14) is in direct engagement with the drive gear (13), and each wheel of the second pair is connected to one of the wheels of the first pair through the corresponding spurious gear (16) (two spurious gears are installed in each line).

The fourth stage of each line includes four leading cylindrical gears (17) of the fourth stage mounted on four shafts (15) of rotation of the driven wheels (14) of the third stage. Moreover, these gears (17) are engaged with a common driven cylindrical wheel (2) to drive the rotor shaft (3).

In the inventive gearbox, torque is also transmitted to the shaft (5) of the tail rotor drive. For this, in each of the two lines on the second shaft (9), a leading bevel gear (18) is installed to drive the tail rotor shaft (5). The specified gear (18) is connected with the driven bevel wheel (19) of the tail shaft drive mounted on the additional shaft (20), which also has an additional leading bevel gear (21) for driving the tail shaft, and this gear (21) is engaged with a common driven spur wheel (4) for driving the tail shaft.

The claimed gearbox provides the transmission of torque to additional units of the helicopter (fan, generator, hydraulic pump, etc.), for which the second shaft (9) of each line is connected to the drive (22) of the box of these units.

Table 1 as an example shows the parameters of the gears (gears) of one of the options for implementing the main gearbox according to the claimed scheme.

The device operates as follows.

The torque from each engine (1) is transmitted through the first input shaft (7) to the drive gear (6) of the first stage, which rotates the driven wheel (8) of the first stage, which drives the second shaft (9). The second shaft (9) transfers rotation to the bevel gear of the second stage (10) to drive the rotor, the bevel gear (18) to drive the tail rotor, as well as the drive (22) of the unit box.

In each line from the gear (18), through additional gears (wheels) (19) and (21) installed on the additional shaft (20), rotation is transmitted to a single driven wheel (4) of the shaft (5) to drive the tail rotor.

The bevel gear (10) of the second reduction stage rotates the bevel wheel (11), which drives the gear (13) of the third stage through the third shaft (12). Due to the use of spurious gears (16), the rotation from the gear (13) is transmitted to the four driven wheels (14) of the third stage, due to which one stream is divided into four streams in each line. At the fourth reduction stage, the torque from each wheel (14) is transmitted via individual shafts (15) to the fourth stage gears (17), which rotate the common driven wheel (2) of the drive shaft drive (3).

Thus, in the claimed device, the separation of two power flows from the drive motors into eight flows, summed on a common driven wheel, which allows to increase the resource of rolling bearings of the shafts (15) of the fourth stage. In addition, the indicated design feature, as well as the general layout of the elements of the kinematic system of the gearbox, reduce the total weight of the structure due to the possibility of reducing the dimensions of the device parts.

Claims (4)

1. A four-stage non-planetary helicopter gearbox containing two transmission lines of torque from two drive motors (1) to a common driven wheel (2) to drive the rotor shaft (3) and a common driven wheel (4) to drive the tail rotor shaft (5) wherein each of the lines contains a driving gear (6) of the first stage mounted on the first input shaft (7) connected to the engine (1), and a driven wheel (8) of the first stage mounted on the second shaft (9) and located in meshing with said pinion gear (6), pinion gear (10) in of the second stage mounted on the second shaft (9), and the second wheel driven wheel (11) located on the third shaft (12), mounted on the third shaft (12), the drive gear (13) of the third stage mounted on the third shaft (12), the first a pair of driven wheels (14) of the third stage engaged with said gear (13), and a second pair of driven wheels (14) of the third stage connected to the first pair through spurious gears (16), four driving gears (17) of the fourth stage, mounted on the shafts (15) of the rotation of the driven wheels (14) of the third stage and located I am engaged with the common driven wheel (2) of the rotor shaft (3), while in each of the indicated lines the second shaft (9) is connected to the drive (22) of the helicopter assembly box, and the pinion gear is installed on the second shaft (9) ( 18) to drive the tail rotor shaft. 2. The gearbox according to claim 1, characterized in that the driving gears (6,13,17) of the first, third and fourth stages, as well as the driven wheels (8,14) of the first and third stages are cylindrical, and the driving gears (10) and the driven wheels (11) of the second stage are made conical. 3. The gearbox according to claim 1, characterized in that the drive gears (18) for driving the tail shaft of each line are made conical. 4. The gearbox according to claim 3, characterized in that in each line the drive gear (18) for driving the tail shaft is engaged with the driven bevel wheel (19) of the tail shaft drive mounted on the additional shaft (10), and on the additional shaft an additional driving bevel gear (21) for driving the tail shaft is also installed, which is meshed with a common driven wheel (4) for driving the tail shaft.

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